,illu/ration3 ,,d5v]1 ,,colorado ,b f ^! imm5se prairies may arise "o great advantage to ! ,unit$ ,/ates1 viz41 ! re/riction ( our population to "s c]ta9 limits1 & !reby a cont9uation ( ! union4 ,our citiz5s be+ s prone to rambl+1 & ext5d+ !mselves on ! fronti]s1 w1 ?r\gh necessity1 be con/ra9$ to limit _! ext5t on ! we/ to ! bord]s ( ! ,miss\ri & ! ,mississippi1 :ile !y leave ! prairies1 incapable ( cultivation1 to ! w&]+ & unciviliz$ ,aborig9es ( ! c\ntry4 ,zebulon ,pike ,exploratory ,travels ,?r\gh ,! ,we/]n ,t]ritories ( ,nor? ,am]ica compris+ a voyage f ,/4 ,l\is1 on ! ,mississippi1 to ! s\rce ( t riv]1 & a j\rney ?r\gh ! int]ior ( ,l\isiana & ! nor?-ea/]n prov9ces ( ,new ,spa94 ,p]=m$ 9 ! ye>s #ahje1 #ahjf1 & #ahjg1 by ord] ( ! ,gov]nm5t ( ! ,unit$ ,/ates4 ,by ,zebulon ,montgom]y ,pike4 ,publi%$ by ,pat]no/]-,r[1 ,london1 #ahaa3 ,w4 ,h4 ,lawr5ce & ,company1 ,d5v]1 #ahhi4 ,quotation f pages #bcj-bca1 #ahhi edition4 ,! ,,geologic ,,/ory ( ,! ,,great ,,pla9s ,by ,,donald ,e4 ,,trimble ,a nonte*nical description ( ! orig9 & evolution ( ! l&scape ( ! ,great ,pla9s ,,geological ,,survey ,,bullet9 #adic ,,unit$ ,,/ates ,,dep>tm5t ,,( ,,! ,,int]ior ,,cecil ,d4 ,,&rus1 ,secret>y ,,geological ,,survey ,h4 ,william ,m5>d1 ,director ,illu/ration3 ,u4 ,s4 ,,dep>tm5t ,,( ,,! ,,int]ior ,m>* #c1 #ahdi ,,unit$ ,,/ates ,,gov]nm5t ,,pr9t+ ,,(fice1 ,,wa%+ton3 #aihj ,libr>y ( ,congress ,catalog+ 9 ,publication ,data ,trimble1 ,donald ,e4 ,! geologic /ory ( ! ,great ,pla9s4 7,u4,s4 ,geological ,survey ,bullet9 #adic7 ,bibliography3 p4 #ej ,includes index4 ,supt4 ( ,docs4 no43 ,i #ai4c3 #adic ,i4 ,geology--,great ,pla9s4 ,i4 ,title4 ,,ii4 ,s]ies3 ,unit$ ,/ates ,geological ,survey ,bullet9 #adic4 ,,qe#ge4;,b#i no4 #adic ,,qe#ga #eeg4cs #eeg4h #hj-fjgjbb ,= sale by ! ,sup]9t5d5t ( ,docum5ts1 ,u4,s4 ,gov]nm5t ,pr9t+ ,(fice ,wa%+ton1 ,d4,c4 #bjdjb ,,cont5ts ,introduction #a ,:at is ! ,great ,pla9s8 #e ,! ,great ,pla9s--its p>ts #g ,e>ly hi/ory #aj ,w>p+ & /ream deposition #aa ,sculptur+ ! l& #ah ,l&=ms ( today--,! surface features ( ! ,great ,pla9s #ai ,black ,hills #bj ,c5tral ,texas ,uplift #bb ,raton ,section #bc ,high ,pla9s #be ,miss\ri ,plateau #cb ,preglacial ,dra9age #cc ,glaciat$ ,miss\ri ,plateau #cc ,unglaciat$ ,miss\ri ,plateau #cf ,! ,colorado ,pi$mont #db ,pecos ,valley #de ,edw>ds ,plateau #df ,pla9s ,bord] ,section #dh ,epilogue #di ,ackn[l$gm5ts #di ,"s s\rce ref]5ces #ej ,,figures ,,frontispiece4 ,a]ial photograph ( ,d5v]4 #a4 ,index map #c #b-c4 ,maps %[+3 #b4 ,physical divisions ( ! ,unit$ ,/ates & maximum ext5t ( ! cont95tal ice %eets #f #c4 ,! ,great ,pla9s prov9ce & its sections #h #d4 ,photograph ( ,mescal]o esc>pm5t & s\!rn ,high ,pla9s #i #e4 ,geologic "t *>t #ab #f-h4 ,maps %[+3 #f4 ,paleogeography ( ,u4,s4 9 ,late ,cretace\s #ad #g4 ,/ructural sett+ ( ! ,great ,pla9s #ad #h4 ,progressive s\?w>d expansion ( areas ( deposition #ag #i4 ,photograph ( ,big ,horn /rip m9e at ,acme1 ,wyo4 #ah #aj4 ,black ,hills diagram #ba #aa-af4 ,photographs %[+3 #aa4 ,wea!r+ ( granite at ,sylvan ,lake 9 ! ,black ,hills #bb #ab4 ,capul9 ,m\nta9 ,national ,monum5t1 ,n4 ,mex4 #bd #ac4 ,mesa de ,maya1 ,colo4 #be #ad4 ,spani% ,peaks1 ,colo4 #bf #ae4 8,! ,gangplank10 ,wyo4 #bg #af4 ,scotts ,bluff ,national ,monum5t1 ,nebr4 #bh #ag4 ,a]ial photograph ( ! ,nebraska ,s& ,hills #cj #ah4 ,map ( ! ,nebraska ,s& ,hills #ca #ai-cj4 ,photographs %[+3 #ai4 ,loess pla9 9 ,nebraska #cb #bj4 ,gr\nd mora9e on ! ,coteau du ,miss\ri 9 ,nor? ,dakota #cd #ba4 ,slump blocks 9 ,nor? ,unit ( ,!odore ,roosevelt ,national ,memorial ,p>k1 ,n4 ,dak4 #cf #bb4 ,highwood ,m\nta9s1 ,mont4 #cg #bc4 ,devils ,t[] ,national ,monum5t1 ,wyo4 #ch #bd4 ,glaciat$ valley 9 ,crazy ,m\nta9s1 ,mont4 #ci #be4 ,p[d] ,riv] ,bas9 9 vic9ity ( ,tongue ,riv] #dj #bf4 ,badl&s ,national ,monum5t1 ,s4 ,dak4 #da #bg4 ,badl&s ( ,little ,miss\ri ,riv] 9 ,s\? ,unit ( ,!odore ,roosevelt ,national ,memorial ,p>k1 ,n4 ,dak4 #db #bh4 ,hogback ridges along ! ,front ,range1 ,colo4 #dc #bi4 ,pawnee ,buttes1 ,colo4 #dd #cj4 ,edw>ds ,plateau1 ,tex4 #dg ,,table #a4 ,g5]aliz$ *>t ( rocks ( ! ,great ,pla9s #ae ,! ,,geologic ,,/ory ( ,! ,,great ,,pla9s ,by ,donald ,e4 ,trimble ,,introduction ,! ,great ,pla9s6 ,! words alone create a s5se ( space & a feel+ ( de/9y--a *all5ge4 ,b :at exactly is ?is special "p ( ,we/]n ,am]ica t conta9s s mu* ( our hi/ory8 ,h[ did x come to be8 ,:y is x diff]5t8 ,geographically1 ! ,great ,pla9s is an imm5se sweep ( c\ntry2 x rea*es f ,mexico f> nor? into ,canada & spreads out ea/ ( ! ,rocky ,m\nta9s l a huge welcome mat4 ,s (t5 malign$ z a drab1 featureless area1 ! ,great ,pla9s is 9 fact a l& ( m>k$ contra/s & limitless v>iety3 canyons c>v$ into solid rock ( an arid l& by ! wat]s ( ! ,pecos & ! ,rio ,gr&e2 ! seem+ly endless gra9fields ( ,kansas2 ! desolation ( ! ,badl&s2 ! beauty ( ! ,black ,hills4 ,be=e x 0 brok5 by ! pl[1 mo/ ( ! ,great ,pla9s f ! ,texas panh&le nor?w>d 0 treeless grassl&4 ,trees grew only along ! floodpla9s ( /reams & on ! few m\nta9 masses ( ! nor!rn ,great ,pla9s4 ,^! lu% prairies once 7 ! graz+ gr\nd = imm5se h]ds ( bison1 & ! l& provid$ a b\ntiful life = ^? ,indians :o foll[$ ! h]ds4 ,s\? ( ! grassl&s1 9 ,texas1 %rubs mix$ ) ! grasses3 creosote bu% along ! valley ( ! ,pecos ,riv]2 mesquite1 oak1 & junip] to ! ea/4 ,! g5]al lack ( trees sugge/s t ?is is a l& ( little moi/ure1 z inde$ x is4 ,ne>ly all ( ! ,great ,pla9s receives less ?an #bd in*es ( ra9fall a ye>1 & mo/ ( x receives less ?an #af in*es4 ,?is dryness & ! /r5g? ( sun%9e 9 ?is area1 :i* lies mo/ly betwe5 #b1jjj & #f1jjj feet above sea level1 create ! semi>id environm5t t typifies ! ,great ,pla9s4 ,b x 0 n always s4 ,:5 ! la/ cont95tal glaci] /ood ne> its maximum ext5t1 "s #ab1jjj-ad1jjj ye>s ago1 spruce =e/ rea*$ s\?w>d z f> z ,kansas1 & ! ,great ,pla9s f>!r s\? 0 cov]$ by decidu\s =e/4 ,! trees retreat$ nor?w>d z ! ice front rec$$1 & ! ,great ,pla9s has be5 a treeless grassl& = ! la/ #h1jjj-aj1jjj ye>s4 ,= m ?an half a c5tury aft] ,lewis & ,cl>k cross$ ! c\ntry 9 #ahje-f1 ! ,great ,pla9s 0 ! te/+ gr\nd ( fronti] ,am]ica--"h ,am]ica grew to maturity 7fig4 #a74 ,9 #ahje-g1 explor] ,zebulon ,pike cross$ ! s\?-c5tral ,great ,pla9s1 foll[+ ! ,arkansas ,riv] f ne> ,great ,b5d1 ,kans41 to ! ,rocky ,m\nta9s4 ,9 lat] ye>s1 ,santa ,fe trad]s1 lur$ by ! weal? ( ,new ,mexican trade1 foll[$ ,pike's pa? z f> z ,b5ts ,=t1 ,colo41 :]e !y turn$ s\?we/w>d away f ! riv] r\te4 ,^? pione]s :o lat] cross$ ! pla9s on ! ,oregon ,trail rea*$ ! ,platte ,riv] ne> ! place t w\ld become ,ke>ney1 ,nebr41 by a ne>ly direct r\te f ,indep5d5ce1 ,mo41 & foll[$ ! ,platte across ! c5tral "p ( ! ,great ,pla9s4 ,al?\gh ^! r\tes may h seem$ long & t$i\s to ^? du/y travel]s1 !y provid$ relatively easy access to ! ,rocky ,m\nta9s & _h a cont9u\s supply ( fre% wat]1 an absolute necessity 9 ^! pla9s4 ,! m9ds ( ^? fronti]sm5 surely 7 occupi$ ) ! dang]s & dem&s ( ! mom5t--& ) dreams--b ! "t af=d$ by ! sl[ pace ( travel also gave !m ample opportunity = ?\ght ab\t ! orig9s ( _! surr\nd+s4 ,today's travel]1 :o has less "t = contemplation1 races pa/ a *ang+ kaleidoscope ( l&scape4 ,! increas$ aw>5ess creat$ by ?is rapidity ( *ange p]haps is ev5 m likely to /imulate que/ions ab\t ! orig9 ( ?is l&scape4 ,illu/ration3 ,figure #a4--;,index map ( ! ,great ,pla9s %[+ r\te ( ,lewis & ,cl>k & ! ,santa ,fe & ,oregon ,trails4 ,= in/ance1 ! we/b\nd travel] on ,int]/ate ,highway #gj trav]ses ne>ly a ?\s& miles ( l[1 r\nd$ hills aft] leav+ ! ,appala*ians2 ! roll+ l&scape is brok5 only by a few flat areas :]e glacial ice or small lakes once /ood4 ,sudd5ly1 ne> ,sal9a1 ,kans41 ! obs]vant travel] s5ses a diff]5ce 9 ! l&scape4 ,in/ead ( r\nd$ hills1 widely or closely spac$1 he sees on ! skyl9e flat surfaces1 or remnants ( flat surfaces4 ,z he climbs g5tly we/w>d ^! brok5 horizontal l9es /& et*$ aga9/ ! sky4 ,ab\t #ce miles we/ ( ,sal9a he f9ds himself on a broad1 flat plateau1 :]e seem+ly he c see =ev]4 ,true1 9 places he desc5ds into /ream valleys1 b only briefly1 = he soon climbs back onto ! flat surface4 ,?is plateau surface cont9ues = #cjj miles to ! we/--to )9 #ajj miles ( ! abrupt front ( ! ,rocky ,m\nta9s4 ,ea/-fl[+ /reams1 su* z ! ,smoky ,hill1 ! ,sal9e1 ! ,solomon1 & ! ,republican ,riv]s & _! tribut>y bran*es1 h cut _! valleys into ?is surface1 b ^! valleys become increas+ly %all[ & disappe> entirely ne> ! we/]n rim ( ! plateau 9 ea/]n ,colorado4 ,! di/ant peaks ( ! ,rockies are se5 = ! fir/ "t z ! travel] approa*es ! esc>pm5t t =ms ! we/]n edge ( ?is great plateau4 ,aft] cross+ ! esc>pm5t ne> ,limon1 ,colo41 he beg9s ! long g5tle desc5t to ,d5v]1 on ! ,s\? ,platte ,riv] ne> ! foot ( ! m\nta9s t loom s awesomely ahead4 ,he has cross$ ! ,great ,pla9s4 ,! di/ances h be5 great1 b ! contra/s h be5 m>k$4 ,_h our travel] select$ a diff]5t r\te1 ei!r to ! nor? or s\?1 he w\ld h f\nd ev5 great] contra/s1 = ! ,great ,pla9s has _m p>ts1 ea* ) its own di/9ctive aspect4 ,:y %\ld su* div]se l&scapes be consid]$ p>ts ( ! ,great ,pla9s8 ,:at are _! unify+ features8 ,& :at creat$ ?is l&scape8 ,has x always be5 ?is way8 ,if n1 :5 0 x =m$8 ,h[ 0 x =m$8 ,we w look "h at "s ( ! answ]s to ^? que/ions4 ,! hi/ory ( ev5ts t produc$ ! l&scape ( ! ,great ,pla9s is int]pret$ bo? f ! mat]ials t compose ! l&=ms & f ! l&=ms !mselves4 ,z we w see1 all l&=ms are ! result ( geologic processes 9 action4 ,^! processes det]m9e n only ! size & %ape ( ! l&=ms1 b also ! mat]ials ( :i* !y are made4 ,^! geologic processes1 :i* =m & %ape our ,e>?'s surface1 are simply ! inevitable actions ( ! re/less int]ior ( ! ,e>? & ( ! air1 wat]1 & c>bon dioxide ( ! atmosph]e1 aid$ by gravity & sol> heat+ 7or lack ( x74 ,!y all h help$ sculpture ! fasc9at+ div]sity ( ! "p ( our l& we call ! ,great ,pla9s4 ,,:at ,,is ,,! ,,great ,,pla9s8 ,! ,unit$ ,/ates has be5 subdivid$ into physiographic regions t1 al?\gh !y h great div]sity )9 !mselves1 are di/9ctly diff]5t f ea* o!r 7fig4 #b74 ,f ! ,rocky ,m\nta9s on ! we/ to ! ,appala*ians on ! ea/1 ! int]ior ( our c\ntry is a va/ l[l& 7see cov]7 kn[n z ! ,int]ior ,pla9s4 ,^! pla9s are b\nd$ on ! s\? by a region ( ,int]ior ,highl&s1 consi/+ ( ! ,oz>k ,plateaus & ! ,oua*ita prov9ce1 & by ! ,coa/al ,pla94 ,9 ! ,great ,lakes region1 ! ,int]ior ,pla9s laps onto ! mo/ anci5t "p ( ! cont95t1 ! ,sup]ior ,upl&4 ,we/ ( ! ,great ,lakes x ext5ds f> to ! nor? into ,canada4 ,c]ta9ly ! ,rocky ,m\nta9s are di/9ctly diff]5t f ! region to ! ea/1 :i* is ! ,great ,pla9s4 ,! ,great ,pla9s1 !n1 is ! we/]n "p ( ! great ,int]ior ,pla9s4 ,! ,rocky ,m\nta9s =m its we/]n m>g94 ,b :at det]m9es its ea/]n m>g98 ,dur+ ! ,plei/oc5e ,epo* or ,great ,ice ,age1 huge glaci]s =m$ 9 ,canada & advanc$ s\?w>d into ! great1 c5tral1 l[-ly+ ,int]ior ,pla9s ( ! ,unit$ ,/ates4 7,see figure #b47 ,^! glaci]s & _! deposits modifi$ ! surface ( ! l& !y cov]$1 mo/ly betwe5 ! ,miss\ri & ! ,ohio ,riv]s2 !y smoo!d ! cont\rs & gave ! l& a m subdu$ aspect ?an x _h be=e !y came4 ,?is glacially smoo!d & modifi$ l& is call$ ! ,c5tral ,l[l&4 ,al?\gh ! ice %eets lapp$ onto ! nor!rn "p1 ! ,great ,pla9s is ! l>gely unglaciat$ region t ext5ds f ! ,gulf ,coa/al ,pla9 9 ,texas nor?w>d into ,canada betwe5 ! ,c5tral ,l[l& & ! foot ( ! ,rocky ,m\nta9s4 ,its ea/]n m>g9 9 ,texas & ,oklahoma is m>k$ by a prom95t esc>pm5t1 ! ,caprock esc>pm5t4 ,its s\!rn m>g91 :]e x abuts ! ,coa/al ,pla9 9 ,texas1 is at ano!r abrupt rise or sc>p along ! ,balcones fault zone4 ,illu/ration3 ,figure #b4--,physical divisions ( ! ,unit$ ,/ates & maximum ext5t ( ! cont95tal ice %eets dur+ ! ,great ,ice ,age4 ,,! ,,great ,,pla9s--,,its ,,p>ts ,)9 ! ,great ,pla9s are _m l>ge areas t diff] greatly f adjo9+ areas 7fig4 #c74 ,! ,black ,hills /&s out di/9ctively f ! surr\nd+ l[] l&1 & its d>k1 =e/$ prom95ce c be se5 = scores ( miles f any direction4 ,at ! s\!rn end ( ! ,great ,pla9s is ano!r1 less impos+1 =e/$ prom95ce--! ,c5tral ,texas ,uplift4 ,mo/ impressive1 p]haps1 is ! huge1 ne>ly flat plateau kn[n z ! ,high ,pla9s1 :i* ext5ds s\?w>d f ! nor!rn bord] ( ,nebraska ?r\gh ! ,panh&le ( ,texas1 & :i* =ms ! c5tral "p ( ! ,great ,pla9s4 ,! ea/ & we/ rims ( ! s\!rn ,high ,pla9s are at high1 cliff$1 erosional esc>pm5ts--! ,caprock esc>pm5t on ! ea/ & ! ,mescal]o esc>pm5t on ! we/4 ,! nor? edge ( ! ,high ,pla9s is def9$ by ano!r esc>pm5t1 ! ,p9e ,ridge esc>pm5t1 :i* sep>ates ! ,high ,pla9s f a region t has be5 greatly dissect$ by ! ,miss\ri ,riv] & its tribut>ies4 ,!re1 sev]al levels ( roll+ upl& are surm\nt$ by small m\nta9\s masses & flat-topp$ buttes & are entr5*$ by /reams4 ,?is region is ! ,miss\ri ,plateau4 ,! cont95tal glaci] lapp$ onto ! nor!a/]n "p ( ! ,miss\ri ,plateau & alt]$ its surface4 ,! ,s\? ,platte & ,arkansas ,riv]s & _! tribut>ies h simil>ly dissect$ an area along ! m\nta9 front t is call$ ! ,colorado ,pi$mont1 & ! ,pecos ,riv] has excavat$ a broad valley tr5d+ s\?w>d f ! ,sangre de ,cri/o ,m\nta9s 9 ,new ,mexico into ,texas4 ,! ,mescal]o esc>pm5t sep>ates ! ,pecos ,valley f ! s\!rn ,high ,pla9s 7fig4 #d74 ,s\? & ea/ ( ! ,pecos ,valley1 ext5d+ to ! ,rio ,gr&e & ! ,coa/al ,pla91 is a broad plateau ( b>e1 /ripp$1 flat-ly+ lime/one lay]s be>+ little b cactus t is call$ ! ,edw>ds ,plateau4 ,gre51 crop-fill$ valleys ) g5tly slop+ valley walls & r\nd$ /ream divides tr5d ea/w>d f ! ,high ,pla9s ( we/]n ,kansas & *>act]ize a ,pla9s ,bord] section4 ,& f9ally1 betwe5 ! ,colorado ,pi$mont on ! nor? & ! ,pecos ,valley on ! s\?1 volcanic v5ts1 c9d] cones1 & lava fields =m ano!r di/9ctive t]ra9 9 ! "p ( ! ,great ,pla9s call$ ! ,raton section4 ,illu/ration3 ,figure #c4--,! ,great ,pla9s prov9ce & its sections4 ,illu/ration3 ,figure #d4--,mescal]o esc>pm5t & ! s\!rn ,high ,pla9s 7,llano ,e/acado7 s\? ( ,tucumc>i1 ,n4 ,mex41 ,photograph by ,c4 ,d4 ,mill]1 ,u4 ,s4 ,geological ,survey4 ,c su* div]se p>ts ( our l& h a suffici5tly common orig9 to ju/ify _! be+ consid]$ "p ( "o unifi$ :ole--! ,great ,pla9s8 ,probably s1 b to und]/& :y1 we mu/ exam9e "s ( ! e>li] geologic hi/ory ( ! ,great ,pla9s z well z subsequ5t ev5ts reveal$ 9 ! pres5t l&=ms4 ,we w f9d t all p>ts ( ?is region we call ! ,great ,pla9s h a simil> e>ly hi/ory1 & t ! diff]5ces we see are ! results ( local dom9ance ( c]ta9 processes 9 ! ultimate %ap+ ( ! l&scape1 mo/ly dur+ ! la/ few million ye>s4 ,! di/9ctive "* ( ! l&scape 9 ea* section is det]m9$ 9 "p by bo? ! e>ly ev5ts & ! lat] %ap+ processes4 ,,e>ly ,,hi/ory ,! ,int]ior ,pla9s1 ( :i* ! ,great ,pla9s is ! we/]n1 mo/ly unglaciat$ "p 7fig4 #b71 is ! lea/ complicat$ "p ( our cont95t geologically except = ! ,coa/al ,pla94 ,= mo/ ( ! half billion ye>s f #egj million 7fig4 #e7 until ab\t #gj million ye>s ago1 %all[ seas lay across ! int]ior ( our cont95t 7fig4 #f 74 ,a ?ick sequ5ce ( lay]$ s$im5ts1 mo/ly betwe5 #e1jjj & #aj1jjj feet ?ick1 b m 9 places1 0 deposit$ onto ! subsid+ floor ( ! int]ior ocean 7table #a74 ,^! s$im5ts1 n[ consolidat$ into rock1 re/ on a floor ( v old rocks t are mu* l ! anci5t rocks ( ! ,sup]ior ,upl&4 ,ab\t #gj million ye>s ago ! seas 7 displac$ f ! cont95tal int]ior by sl[ uplift ( ! cont95t1 & ! l&scape t appe>$ 0 simply ! ext5sive1 ne>ly flat floor ( ! =m] sea4 ,,w>p+ ,,& ,,/ream ,,deposition ,mo/ ( ^! rocks ( m>9e orig9 lie at consid]able dep? b5ea? ! l& surface1 conceal$ by an ov]ly+ ?ick1 lay]$ sequ5ce ( rocks laid d[n by /reams1 w9d1 & glaci]s4 ,nev]!less1 _! geologic "*1 position1 & =m are exceptionally well kn[n f in=mation ga9$ f ?\s&s ( wells t h be5 drill$ = oil4 ,! initial1 ne>ly horizontal position ( ! lay]s ( rock b5ea? ! ,int]ior ,pla9s has be5 little di/urb$ except :]e m\nta9s l ! ,black ,hills 7 uplift$ ab\t #gj million ye>s ago4 ,at ^? places1 :i* are all 9 ! nor!rn & s\!rn p>ts ( ! ,great ,pla9s1 ! s$im5t>y lay]s h be5 w>p$ up & locally brok5 by ! rise ( hot molt5 rock f dep?4 ,else:]e 9 ! ,int]ior ,pla9s1 h[ev]1 e>? =ces ( ab\t ! same p]iod caus$ only a reemphasis ( g5tle undulations 9 ! ,e>?'s cru/4 ,^! undulations affect$ bo? ! old] basem5t rocks & ! ov]ly+ s$im5t>y rocks1 & !y take ! =m ( g5tle bas9s & ar*es t 9 "s places span sev]al ,/ates4 7,see sket* map1 figure #g47 ,a s]ies ( n>r[ bas9s lies along ! m\nta9 front on ! we/ side ( ! ,great ,pla9s4 ,a broad1 discont9u\s ar* ext5ds s\?we/ f ! ,sup]ior ,upl& to ! ,rocky ,m\nta9 front to =m a buri$ divide t sep>ates ! l>ge ,willi/on bas9 on ! nor? f ! ,anad>ko bas9 to ! s\?4 ,:ile ! flat-ly+ lay]s ( ! ,int]ior ,pla9s 7 be+ only g5tly w>p$1 va/ly diff]5t e>? movem5ts 7 tak+ place f>!r we/1 9 ! area ( ! pres5t ,rocky ,m\nta9s4 ,along a relatively n>r[ nor?-tr5d+ belt1 ext5d+ f ,mexico to ,alaska1 ! l& 0 be+ uplift$ at a great rate4 ,! lay]s ( s$im5t>y rock deposit$ 9 ! inl& sea 7 /ripp$ f ! cre/ ( ! ris+ m\nta9\s belt by erosion & transport$ to its flanks z ! gravel1 s&1 & mud ( /reams & riv]s4 ,?is transport$ s$im5t 0 deposit$ on ! pla9s to =m ! rocks ( ! ,cretace\s ,hell ,creek1 ,lance1 ,l>amie1 ,v]mejo1 & ,raton ,=mations4 ,vegetation ?riv$ on ?is alluvial pla91 & ?ick accumulations ( woody debris 7 buri$ to ultimately become coal4 ,?is lu% vegetation provid$ ample food = ! hordes ( ?ree-horn$ d9osaurs 7,tric]atops7 t roam$ ^! pla9s4 ,_! fossiliz$ rema9s are f\nd f ,canada to ,new ,mexico4 ,illu/ration3 ,figure #e4--;,geologic "t *>t & ! progression ( life =ms4 ,note ,cretace\s ,tric]atops1 ,oligoc5e ,titano!res1 & ,mioc5e ,moropus4 ,,geologic ,,"t ,! ,age ( ! ,e>? ,! ,e>? is v old--#d4e billion ye>s or m accord+ to rec5t e/imates4 ,mo/ ( ! evid5ce = an anci5t ,e>? is conta9$ 9 ! rocks t =m ! ,e>?'s cru/4 ,! rock lay]s !mselves--l pages 9 a long & complicat$ hi/ory--record ! surface-%ap+ ev5ts ( ! pa/1 & buri$ )9 !m are traces ( life--! plants & animals t evolv$ f organic /ructures t exi/$ p]haps #c billion ye>s ago4 ,also conta9$ 9 rocks once molt5 are radioactive elem5ts ^: isotopes provide ,e>? sci5ti/s ) an atomic clock4 ,)9 ^! rocks1 8p>5t0 isotopes decay at a pr$ictable rate to =m 8daught]0 isotopes4 ,by det]m9+ ! relative am\nts ( p>5t & daught] isotopes1 ! age ( ^! rocks c be calculat$4 ,?us1 ! results ( /udies ( rock lay]s 7/ratigraphy71 & ( fossils 7paleontology71 c\pl$ ) ! ages ( c]ta9 rocks z measur$ by atomic clocks 7geo*ronology71 atte/ to a v old ,e>?6 ,illu/ration3 ,figure #f4--;,g5]aliz$ paleogeographic map ( ! ,unit$ ,/ates 9 ,late ,cretace\s "t 7#fe to #hj million ye>s ago71 :5 mo/ ( ! ,great ,pla9s 0 b5ea? ! sea4 ,illu/ration3 ,figure #g4--,/ructural sett+ ( ! ,great ,pla9s4 ,willi/on bas9 & ,anad>ko bas9 are sep>at$ by a midcont95tal ar*4 ,illu/ration3 ,table #a4--;,g5]aliz$ *>t ( rocks ( ! ,great ,pla9s ,geologic age ,miss\ri ,high ,pla9s--,pla9s ,pecos ,millions ( ,plateau--,black ,bord]--,colorado ,valley--,edw>ds ye>s ago ,hills ,pi$mont ,plateau--,c5tral ,texas ,quat]n>y ,plei/oc5e ,glacial deposits1 ,alluvium1 s& ,pi$mont1 t]race1 alluvium1 & dunes1 & loess & bolson t]race deposits deposits #b erosional surface ,t]ti>y ,plioc5e ,,erosion #e ,flaxville ,gravel ,ogallala =mation & ,ogallala ,=mation ,mioc5e ,arik>ee ,=mation ,arik>ee ,=mation #bb-bd erosional surface ,oligoc5e ,:ite ,riv] ,gr\p ,:ite ,riv] ,gr\p ,mo/ly miss+ because ( erosion or nondeposition #cg-ch erosional surface ,eoc5e ,wasat* & ,gold5 ,valley ,=mations #ec-ed ,dawson ,arkose ,paleoc5e ,=t ,union ,d5v]1 ,poison ,=mation ,canyon1 & ,raton ,=mations #fe ,cretace\s ,hell ,creek & ,v]mejo & ,l>amie ,lance ,=mations ,=mations ,fox ,hills ,s&/one ,tr9idad & ,fox ,hills ,s&/ones ,%ales1 s&/ones1 & lime/ones deposit$ 9 ,late ,cretace\s sea ,dakota ,s&/one ,dakota ,s&/one & ,lakota ,=mation ,gl5 ,rose & ,edw>ds ,lime/ones #acf ,jurassic ,sundance ,morrison ,=mation ,jurassic rocks n ,=mation1 ,ellis pres5t ,gr\p1 & ,unkpapa ,s&/one #aij-aie ,triassic ,dom9antly r$ rocks #bbe ,,paleozoic ,paleozoic rocks1 undivid$ #egj ,,precambrian ,precambrian rocks1 undivid$ ,z ! m\nta9s cont9u$ to rise1 ! erod+ /reams cut into ! old core rocks ( ! m\nta9s1 & t debris too 0 c>ri$ to ! flanks & onto ! adjo9+ pla9s4 ,! m\nta9\s belt cont9u$ to rise int]mitt5tly1 & volcanoes began to appe> ab\t #ej million ye>s ago4 ,toge!r1 ! m\nta9s & volcanoes provid$ huge quantities ( s$im5t1 :i* ! /reams transport$ to ! pla9s & deposit$4 ,! areas ne>e/ ! m\nta9s 7 cov]$ by s$im5ts ( ,late ,cretace\s & ,paleoc5e age 7table #a7--! ,poison ,canyon ,=mation to ! s\?1 ! ,dawson & ,d5v] ,=mations 9 ! ,d5v] area1 & ! ,=t ,union ,=mation to ! nor? 7fig4 #h74 ,vegetation cont9u$ to fl\ri%1 especially 9 ! nor!rn "p ( ! ,great ,pla9s1 & 0 buri$ to =m ! ?ick lignite & subbitum9\s coal b$s ( ! ,=t ,union ,=mation 7fig4 #i74 ,! e>lie/ mammals1 mo/ ( ^: rema9s come f ! ,paleoc5e ,=t ,union ,=mation1 h few mod]n survivors4 ,beg9n+ ab\t #de million ye>s ago1 9 ,eoc5e "t1 !re 0 a long p]iod ( /ability la/+ p]haps #aj million ye>s1 :5 !re 0 little uplift ( ! m\nta9s &1 !re=e1 little deposition on ! pla9s4 ,a widespread & /rongly develop$ soil =m$ ov] mu* ( ! ,great ,pla9s dur+ ?is p]iod ( /ability4 ,) r5ew$ uplift & volcanism 9 ! m\nta9s at ! end ( ?is p]iod1 great quantities ( s$im5t aga9 7 c>ri$ to ! pla9s by /reams & spread ov] ! nor!rn ,great ,pla9s & s\!a/w>d to ! ar* or divide sep>at+ ! ,willi/on & ,anad>ko bas9s 7fig4 #h74 ,^? s$im5ts =m ! ,:ite ,riv] ,gr\p1 9 :i* ! ,s\? ,dakota ,badl&s are c>v$4 ,9 addition to ! ,titano!res1 huge bea/s ) l>ge1 long horns on _! sn\ts :o liv$ only dur+ ! ,oligoc5e 7#cg to #bb million ye>s ago71 va/ h]ds ( camels1 rh9oc]oses1 horses1 & tapirs--animals n[ f\nd native only on o!r cont95ts--graz$ ^? ,oligoc5e semi>id grassl& pla9s4 ,illu/ration3 ,figure #h4--,progressive s\!a/w>d expansion ( areas cov]$ by ,paleoc5e1 ,oligoc5e1 & ,mioc5e-,plioc5e s$im5t>y deposits4 ,p[d] ,riv] bas9 ,d5v] bas9 ,raton bas9 ,,pla9s ,m>g9 ( ,oligoc5e deposition ,m>g9 ( ,mioc5e-,plioc5e deposition ,illu/ration3 ,figure #i4--;,big ,horn coal /rip m9e 9 ,=t ,union ,=mation at ,acme1 ,wyo4 ,photograph by ,f4 ,w4 ,o/]wald1 ,u4,s4 ,geological ,survey4 ,sometime betwe5 #bj & #cj million ye>s ago ! /reams began deposit+ s& & gravel beyond ! divide1 &1 = ano!r #aj million ye>s or m1 /ream s$im5ts ( ! ,arik>ee & ,ogallala ,=mations spread ov] ! entire ,great ,pla9s f ,canada to ,texas1 except :]e m\nta9\s areas su* z ! ,black ,hills /ood above ! pla9s4 ,betwe5 #e & #aj million ye>s ago1 !n1 ! entire ,great ,pla9s 0 an ea/w>d-slop+ depositional pla9 surm\nt$ only by a few m\nta9 masses4 ,horses1 camels1 rh9oc]oses1 & a /range horselike creature ) claw$ feet 7call$ ,moropus7 liv$ on ?is pla94 ,,sculptur+ ,,! ,,l& ,sometime betwe5 #e & #aj million ye>s ago1 h[ev]1 a great *ange took place1 app>5tly z a result ( regional uplift ( ! entire we/]n "p ( ! cont95t4 ,:ile be=e1 ! /reams _h be5 deposit+ s$im5t on ! pla9s = m ?an #fj million ye>s1 build+ up a huge ?ickness ( s$im5t>y rock lay]s1 n[ ! /reams 7 =c$ to cut d[n into & excavate ! s$im5ts !y _h =m]ly deposit$4 ,z uplift cont9u$--& x may /ill be cont9u+--! /reams cut deep] & deep] into ! lay]$ /ack & develop$ tribut>y sy/ems t excavat$ broad areas4 ,high divides 7 left betwe5 /reams 9 "s places1 & broad plateaus 7 =m$ & rema9 9 o!r places4 ,! great c5tral area 0 ess5tially unt\*$ by erosion & rema9$ /&+ above ! dissect$ areas surr\nd+ x z ! esc>pm5t-rimm$ plateau t is ! ,high ,pla9s4 ,?is d[ncutt+ & excavation by /reams1 !n1 :i* began betwe5 #e & #aj million ye>s ago1 r\gh$ out ! l&scape ( ! ,great ,pla9s & creat$ ! sections we call ! ,miss\ri ,plateau1 ! ,colorado ,pi$mont1 ! ,pecos ,valley1 ! ,edw>ds ,plateau1 & ! ,pla9s ,bord] ,section4 ,ne>ly all ! individual l&=ms t n[ attract ! eye h be5 creat$ by geologic processes dur+ ! la/ #b million ye>s4 ,x truly is a "y l&scape4 ,,l&=ms ,,( ,,today--,! surface features ( ! ,great ,pla9s ,! m\nta9\s sections ( ! ,great ,pla9s 7 =m$ long be=e ! rema9+ areas 7 outl9$ by erosion4 ,uplift ( ! ,black ,hills & ! ,c5tral ,texas ,uplift began z ! cont95tal int]ior 0 rais$ & ! la/ ,cretace\s sea 0 displac$1 #fe to #gj million ye>s ago4 ,!y /ood well above ! surr\nd+ pla9s long be=e any s$im5ts f ! di/ant ,rocky ,m\nta9s began to accumulate at _! bases4 ,9 s\!rn ,colorado & nor!rn ,new ,mexico1 molt5 rock invad$ ! s$im5t>y lay]s betwe5 #bb & #bf million ye>s ago4 ,! ,spani% ,peaks 7 =m$ at ?is "t f hot magma t dom$ up ! surface lay]s b did n break ?r\gh2 ! magma has s9ce cool$ & solidifi$ & has be5 expos$ by erosion4 ,else:]e ! magma rea*$ ! surface1 =m+ volcanoes1 fissures1 & basalt fl[s4 ,a great ?ickness ( basalt fl[s accumulat$ at ,raton ,mesa & ,mesa de ,maya betwe5 #h & #b million ye>s ago4 ,volcanism has cont9u$ int]mitt5tly1 & ! huge c9d] cone ( ,capul9 ,m\nta9 0 creat$ by explosive eruption only #aj1jjj to #d1jjj ye>s ago4 ,mo/ ( ^! volcanic masses 7 =m$ be=e major d[ncutt+ by ! /reams began4 ,o!r igne\s intrusions & volcanic areas 9 ! nor!rn ,great ,pla9s simil>ly 7 =m$ be=e ! /reams 7 incis$4 ,to exam9e ! orig9 ( ! pres5t l&scape & ( ! l&=ms typical ( ! v>i\s sections ( ! ,great ,pla9s1 x is conv5i5t to beg9 ) ! ,black ,hills1 ! ,c5tral ,texas ,uplift1 & ! ,raton section simply because !y 7 =m$ fir/--!y exi/$ be=e ! o!r sections 7 outl9$4 ,,black ,,hills ,! ,black ,hills is a huge1 elliptically dom$ area 9 nor?we/]n ,s\? ,dakota & nor!a/]n ,wyom+1 ab\t #abe miles long & #fe miles wide 7fig4 #aj74 ,rapid ,city1 ,s4 ,dak41 is on ! ,miss\ri ,plateau at ! ea/ edge ( ! ,black ,hills4 ,uplift caus$ erosion to remove ! ov]ly+ cov] ( m>9e s$im5t>y rocks & expose ! granite & metamorphic rocks t =m ! core ( ! dome4 ,! peaks ( ! c5tral "p ( ! ,black ,hills pres5tly are #c1jjj to #d1jjj feet above ! surr\nd+ pla9s4 ,h>ney ,peak1 ) an altitude ( #g1bdb feet1 is ! highe/ po9t 9 ,s\? ,dakota4 ,^! c5tral spires & peaks all are c>v$ f granite & o!r igne\s & metamorphic rocks t =m ! core ( ! uplift4 ,! heads ( f\r ( our great ,presid5ts are sculpt$ f ?is granite at ,m\nt ,ru%more ,national ,memorial4 ,jo9ts 9 ! rocks h controll$ wea!r+ processes t influ5c$ ! f9al %ap+ ( _m ( ^! l&=ms4 ,closely spac$ jo9ts h produc$ ! spires ( ! ,ne$les area1 & widely spac$ jo9ts h produc$ ! r\nd$ =ms ( granite t are se5 ne> ,sylvan ,lake 7fig4 #aa74 ,m>9e s$im5t>y rocks surr\nd+ ! old core rocks =m well-def9$ belts4 ,ly+ aga9/ ! old core rocks & completely surr\nd+ !m are ,paleozoic lime/ones t =m ! ,lime/one ,plateau 7fig4 #aj74 ,^! tilt$ lay]s h /eep erosional sc>ps fac+ ! c5tral "p ( ! ,black ,hills4 ,w9d ,cave & ,jewel ,cave 7 produc$ by gr\nd wat] dissolv+ ^! lime/ones along jo9ts4 ,^! caves are suffici5tly impressive to be designat$ z a national p>k & a national monum5t1 respectively4 ,encircl+ ! ,lime/one ,plateau is a cont9u\s valley cut 9 s(t ,triassic %ale4 ,?is valley has be5 call$ 8! ,racetrack10 because ( its cont9uity1 & ! ,r$ ,valley1 because ( its color4 ,surr\nd+ ! ,r$ ,valley is an out] hogback ridge =m$ by ! tilt$ lay]s ( ! ,dakota ,s&/one1 :i* are q h>d & resi/ant to erosion4 ,/reams t fl[ f ! c5tral "p ( ! ,black ,hills pass ?r\gh ! ,dakota hogback 9 n>r[ gaps4 ,illu/ration3 ,figure #aj4--;,diagram ( ! ,black ,hills uplift by ,a4 ,n4 ,/rahl] 7,/rahl] & ,/rahl]1 #aigh74 ,us$ by p]mission4 ,dakota ,s&/one hogback ,lime/one plateau ,belle ,f\r*e ,riv] ,spe>fi% ,be> ,butte ,sundance ,r$ ,valley ,rapid ,city ,r$ ,valley ,hot ,spr+s ,*ey5ne ,riv] ,edgemont ,mt4 ,ru%more ,national ,monum5t ,jewel ,cave ,national ,monum5t ,w9d ,cave ,national ,p>k ,illu/ration3 ,figure #aa4--;,jo9t$ granite r\nd$ by wea!r+ at ,sylvan ,lake1 9 ! c5tral "p ( ! ,black ,hills1 ,s4 ,dak4 ,! ,black ,hills1 !n1 is an uplift$ area t has be5 c>v$ deeply b diff]5tially by /reams to produce its major outl9es4 ,^? outl9es h be5 modifi$ ma9ly by wea!r+ ( ! anci5t core rocks & solution ( ! lime/one ( ! ,lime/one ,plateau4 ,,c5tral ,,texas ,,uplift ,! dom$ rocks ( ! ,c5tral ,texas ,uplift =m a topography diff]5t f t ( ! ,black ,hills4 ,erosion ( a broad1 uplift$ dome "h has expos$ a core ( old granites1 gneisses1 & s*i/s1 z 9 ! ,black ,hills1 b 9 ! ,c5tral ,texas ,uplift1 erosion has produc$ a topographic bas91 r ?an high peaks & spires1 on ! old rocks ( ! c5tral area4 ,a l[ plateau surface dissect$ into r\nd$ ridges & n>r[ valleys slopes g5tly ea/w>d f ! edge ( ! c5tral area to an esc>pm5t at ! ,balcones fault zone1 :i* det]m9es ! ea/]n edge ( ! ,great ,pla9s "h4 ,nor?we/ ( ! c5tral bas9 ! ,colorado ,riv] fl[s 9 a broad l[l& ab\t #ajj miles long1 b ! nor!rn edge ( ! uplift1 =m+ a divide betwe5 ! ,brazos & ! ,colorado ,riv]s1 is a s]ies ( mesas =m$ ( m resi/ant s&/one & lime/one4 ,! cutt+ action ( /reams1 modifi$ or controll$ 9 "p by diff]5ces 9 h>dness ( ! rock lay]s1 has be5 responsible = ! l&=ms ( ! ,c5tral ,texas ,uplift4 ,wea!r+ ( ! old core rocks has s(t5$ !m suffici5tly to p]mit deep] erosion ( ! c5tral area1 & solution ( lime/one by gr\nd wat] has =m$ su* features z ,longhorn ,cav]ns1 #aa miles s\?we/ ( ,burnet1 ,tex4 ,,raton ,,section ,volcanism *>act]izes ! ,raton section4 ,! volcanic rocks1 :i* =m peaks1 mesas1 & cones1 h armor$ ! old] s$im5t>y rocks & protect$ !m f ! erosion t has cut deeply into ! adjo9+ ,colorado ,pi$mont to ! nor? & ,pecos ,valley to ! s\?4 ,! s\? edge ( ! ,raton section is m>k$ by a spectacul> s\?-fac+ esc>pm5t cut on ! ne>ly flat-ly+ ,dakota ,s&/one4 ,?is esc>pm5t is ! ,canadian esc>pm5t1 nor? ( ! ,canadian ,riv]4 ,nor?w>d = ab\t #ajj miles1 ! l&scape is t ( a ne>ly flat plateau cut on ,cretace\s rock surm\nt$ "h & !re by "y volcanic v5ts1 cones1 & lava fields4 ,capul9 ,m\nta9 is a c9d] cone only #aj1jjj to #d1jjj ye>s old 7fig4 #ab74 ,ne> ! ,new ,mexico-,colorado bord]1 huge piles ( lava 7 erupt$ #h to #b million ye>s ago onto an old]1 high] surface on top ( ei!r ! ,ogallala ,=mation ( ,mioc5e age or ! ,poison ,canyon ,=mation ( ,paleoc5e age4 7,see table #a47 ,^! lava fl[s =m$ a resi/ant cap1 :i* protect$ ! und]ly+ rock f erosion :ile all ! surr\nd+ rock wa%$ away4 ,! result is ! high1 flat-topp$ mesas1 su* z ,raton ,mesa & ,mesa de ,maya 7fig4 #ac71 t n[ =m ! divide betwe5 ! ,arkansas & ,canadian ,riv]s4 ,at ,fi%]s ,peak1 on ! we/ end ( ,raton ,mesa1 ab\t #hjj feet ( basalt fl[s re/ on ! ,poison ,canyon ,=mation at ab\t #h1hjj feet 9 altitude4 ,f>!r ea/1 on ,mesa de ,maya1 ab\t #djj feet ( basalt fl[s ov]lie ! ,ogallala ,=mation at altitudes rang+ f ab\t #f1ejj feet at ! we/ end to ab\t #e1bjj feet at ! ea/ end1 "s #ce miles to ! ea/4 ,! ,ogallala "h re/s on ,cretace\s ,dakota ,s&/one & ,purgatoire ,=mation1 = ! ,poison ,canyon ,=mation 0 remov$ by erosion along ! cre/ ( a local uplift be=e ! ,ogallala 0 deposit$4 ,illu/ration3 ,figure #ab4--;,capul9 ,m\nta9 ,national ,monum5t 9 nor!a/]n ,new ,mexico4 ,?is huge c9d] cone1 :i* erupt$ betwe5 #d1jjj & #aj1jjj ye>s ago1 rises m ?an #a1jjj feet above its base4 ,photograph by ,r4 ,d4 ,mill]1 ,u4,s4 ,geological ,survey4 ,ea/ ( ! belt ( upturn$ s$im5t>y lay]s t =m ! hogback ridges at ! front ( ! ,rocky ,m\nta9s1 ! lay]$ rocks 9 ! ,raton ,bas9 h be5 intrud$ 9 _m places by igne\s bodies1 ! two l>ge/ ( :i* =m ! ,spani% ,peaks 7fig4 #ad71 s\?we/ ( ,wals5burg1 ,colo4 ,^! two peaks are =m$ by igne\s bodies t 7 intrud$ #bf to #bb million ye>s ago & h s9ce be5 expos$ by removal ( ! ov]ly+ s$im5t>y rock lay]s by erosion4 ,radiat+ f ! ,spani% ,peaks are hundr$s ( dikes1 ne>ly v]tical slabs ( igne\s rock t fill$ fractures radiat+ f ! c5t]s ( intrusion4 ,erosion ( ! s$im5t>y lay]s has left _m ( ^! dikes z conspicu\s v]tical walls ( igne\s rock t project high above ! surr\nd+ l& surface4 ,"s ( ^! dikes nor? ( ,tr9idad1 ,colo4 ext5d ea/w>d = ab\t #be miles1 almo/ to ! ,purgatoire ,riv]4 ,illu/ration3 ,figure #ac4--,lava-capp$ ,mesa de ,maya1 ea/ ( ,tr9idad1 ,colo4 ,spani% ,peaks 9 left di/ance4 ,mesa rises ab\t #a1jjj feet above surr\nd+ area4 ,photograph by ,r4 ,b4 ,taylor1 ,u4,s4 ,geological ,survey4 ,! nor!rn b\nd>y ( ! ,raton section is plac$ some:at indef9itely at ! nor!rn limit ( ! area inject$ by igne\s dikes4 ,! ea/]n b\nd>y ( ! ,raton section is at ! ea/]n m>g9 ( ! lavas ( ,mesa de ,maya & adjo9+ mesas1 :]e lava-capp$ outli]s ( ,ogallala ,=mation are sep>at$ f ! ,ogallala ( ! ,high ,pla9s only by ! canyon ( ,c>rizo ,creek4 ,,high ,,pla9s ,at ! end ( ,ogallala deposition1 "s #e million ye>s ago1 ! ,great ,pla9s1 ) ! exception ( ! uplift$ & ! volcanic areas1 0 a va/1 g5tly slop+ pla9 t ext5d$ f ! m\nta9 front ea/w>d to beyond ! pres5t ,miss\ri ,riv] 9 "s places4 ,regional uplift ( ! we/]n "p ( ! cont95t =c$ ! /reams to cut d[nw>d2 l& ne> ! m\nta9s 0 /ripp$ away by ! ,miss\ri1 ! ,platte1 ! ,arkansas1 & ! ,pecos ,riv]s1 & ! ea/]n bord] ( ! pla9s 0 gnaw$ away by less] /reams4 ,a l>ge c5tral area ( ! pla9 is pres]v$1 h[ev]1 ess5tially unt\*$ & unaffect$ by ! /reams1 z a little-modifi$ remnant ( ! depositional surface ( #e million ye>s ago4 ,?is ,ogallala-capp$ pres]v$ remnant ( t uprais$ surface is ! ,high ,pla9s4 ,9 only "o place does t old surface /ill ext5d to ! m\nta9s--at ! s-call$ 8,gangplank0 we/ ( ,*ey5ne1 ,wyo4 7fig4 #ae74 ,9 places1 z at ,scotts ,bluff ,national ,monum5t1 ,nebr4 7fig4 #af71 small fragm5ts ( ?is surface h be5 isolat$ f ! ,high ,pla9s by erosion & n[ /& above ! surr\nd+ area z buttes4 ,illu/ration3 ,figure #ad4--,spani% ,peaks1 s\?we/ ( ,wals5burg1 ,colo4 ,igne\s rocks & _m radiat+ dikes expos$ by erosion4 ,photograph by ,r4 ,b4 ,taylor1 ,u4,s4 ,geological ,survey4 ,illu/ration3 ,figure #ae4--,look+ ea/ t[>d ,*ey5ne at 8! ,gangplank40 ,int]/ate ,highway #hj & ! ,union ,pacific ,railroad foll[ ! ,gangplank f ! ,high ,pla9s 9 ! di/ance onto ! ,precambrian rocks 7old] ?an #egj m4y47 ( ! ,l>amie ,m\nta9s 9 ! =egr\nd4 ,photograph by ,r4 ,d4 ,mill]1 ,u4,s4 ,geological ,survey4 ,illu/ration3 ,figure #af4--;,a]ial view ( ,scotts ,bluff ,national ,monum5t1 ,nebr4 ,buttes on ! s\? side ( ! valley ( ! ,nor? ,platte ,riv] isolat$ by erosion f ,high ,pla9s 9 ! backgr\nd4 ,highe/ butte /&s ab\t #hjj feet above valley floor4 ,! ,high ,pla9s ext5ds s\?w>d f ! ,p9e ,ridge esc>pm5t1 ne> ! ,s\? ,dakota-,nebraska bord] 7fig4 #c71 to ! ,edw>ds ,plateau 9 ,texas4 ,! ,platte1 ! ,arkansas1 & ! ,canadian ,riv]s h cut ?r\gh ! ,high ,pla9s4 ,t "p ( ! ,high ,pla9s s\? ( ! ,canadian ,riv] is call$ ! ,s\!rn ,high ,pla9s1 or ! ,llano ,e/acado 7/ak$ pla974 ,! orig9 ( ?is "n is unc]ta91 b x has be5 sugge/$ t ! t]m ,llano ,e/acado 0 appli$ by e>ly travel]s because ?is "p ( ! ,high ,pla9s is s ne>ly flat & devoid ( l&m>ks t x 0 necess>y = ^? pione]s to set l9es ( /akes to p]mit !m to retrace _! r\tes4 ,! ,llano ,e/acado is b\nd$ on ! we/ by ! ,mescal]o esc>pm5t 7fig4 #d7 & on ! ea/ by ! ,caprock esc>pm5t4 ,! s\!rn m>g9 ) ! ,edw>ds ,plateau is less well def9$1 b ,k+ ,m\nta91 nor? ( ,mc,camey1 ,tex41 is a sc>p-b\nd$ s\!rn promontory ( ! ,high ,pla9s4 ,! rem>kably flat surface ( ! ,llano ,e/acado is abundantly pitt$ by s9ks & depressions 9 ! surface ( ! ,ogallala ,=mation2 ^! 7 =m$ by solution ( ! lime/one by ra9wat] & bl[+ away or deflation by w9d ( ! rema9+ insoluble p>ticles4 ,_m ( ^! solution-deflation depressions are align$ l /r+s ( beads1 sugge/+ t _! location is controll$ by "s k9d ( und]ly+ /ructure1 su* z int]sections ( jo9ts 9 ! ,ogallala ,=mation4 ,! solution-deflation depressions are less abundant nor? ( ! ,canadian ,riv]1 b occur on ! ,high ,pla9s surface nor?w>d to ! ,arkansas ,riv] & along ! ea/]n "p ( ! ,high ,pla9s nor? ( ! ,arkansas to ! ,s\? ,=k ( ! ,republican ,riv]4 ,cov]+ mu* ( ! nor!rn ,high ,pla9s1 h[ev]1 are s& dunes & w9dbl[n silt deposits 7loess7 t mantle ! ,ogallala ,=mation & conceal any solution-deflation depressions t might h =m$4 ,! ,nebraska ,s& ,hills 7fig4 #ag71 ! l>ge/ area ( s& dunes 9 ! we/]n hemisph]e1 is a huge area ( /abiliz$ s& dunes t ext5ds f ! ,:ite ,riv] 9 ,s\? ,dakota s\?w>d beyond ! ,platte ,riv] almo/ to ! ,republican ,riv] 9 we/]n ,nebraska b only to ! ,l\p ,riv] 9 ! nor!a/ "p ( ! ,high ,pla9s 7fig4 #ah74 ,loess cov]s ! we/]n ,high ,pla9s s\?w>d f ! s& dunes almo/ to ! ,arkansas ,riv]1 & to ! ,s\? ,=k ( ! ,republican 9 ! ea/]n "p4 ,?is ext5sive cov] ( loess has creat$ a f]tile l& t makes x an important "p ( ,am]ica's :eatl&s 7fig4 #ai74 ,illu/ration3 ,figure #ag4--;,a]ial view1 look+ nor?we/1 ( ! ,nebraska ,s& ,hills we/ ( ,a%by1 ,nebr4 ,o!r1 small] areas ( s& dunes lie s\? ( ! ,arkansas ,riv] valley4 ,! only l>ge areas ( s& dunes on ! ,llano ,e/acado1 or ,s\!rn ,high ,pla9s1 are along ! s\?we/]n m>g9 ne> ,monahans1 s\?we/ ( ,odessa1 ,tex4 ,oil & gas are pres5t 9 ! ,paleozoic rocks t und]lie ! ,high ,pla9s at dep?4 ,gas fields are ubiquit\s 9 mu* ( ! ea/]n "p ( ! ,high ,pla9s betwe5 ! ,arkansas & ,canadian ,riv]s4 ,j s\? ( ! ,canadian ,riv]1 at ! nor!a/ corn] ( ! ,s\!rn ,high ,pla9s1 a huge oil & gas field has be5 develop$ ne> ,pampa1 ,tex4 ,oil & gas fields also are abundant 9 ! s\?we/]n "p ( ! ,s\!rn ,high ,pla9s1 s\? ( ,littlefield1 ,tex4 ,illu/ration3 ,figure #ah4--,! ,s& ,hills region ( ,nebraska4 ,arr[s %[ inf]r$ direction ( dune-=m+ w9ds4 ,map f ,wright 7#aigj71 us$ by p]mission4 ,,wyom+ ,badl&s ,national ,monum5t ,miss\ri ,riv] ,valley ,,james ,,riv] ,,lobe ,,m9nesota ,,i[a ,,s\? ,,dakota ,,nebraska ,rosebud ,val5t9e ,,des ,,mo9es ,,lobe ,,nebraska ,a%by ,,s&hills ,platte ,riv] ,valley ,,i[a ,,miss\ri ,,nebraska ,,kansas ,,colorado ,muscotah ,,topeka ,,explanation ,transv]se dunes ,longitud9al dunes ,w9d-bl[n s& ,loess ?ickness 79 feet7 ,illu/ration3 ,figure #ai4--,little-modifi$ loess pla9 9 s\!a/]n ,nebraska4 ,photograph by ,judy ,mill]4 ,! surface ( ! ,high ,pla9s1 !n1 has be5 little modifi$ by /reams s9ce ! end ( ,ogallala deposition4 ,x has be5 rais$ by regional uplift & pitt$ by solution & deflation1 & l>ge p>ts ( x h be5 cov]$ by w9d-bl[n s& & silt4 ,x has be5 drill$ = oil & gas & ext5sively f>m$1 b x is /ill a geological r>ity--a pres]v$ l& surface t is #e million ye>s old4 ,,miss\ri ,,plateau ,beg9n+ ab\t #e million ye>s ago1 regional uplift ( ! we/]n "p ( ! cont95t =c$ /reams1 :i* = #cj million ye>s _h be5 deposit+ s$im5t ne>ly cont9u\sly on ! ,great ,pla9s1 to *ange _! behavior & beg9 to cut into ! lay]s ( s$im5t !y s long _h be5 deposit+4 ,! pr$ecessor ( ! ,miss\ri ,riv] ate headw>d into ! nor!rn ,great ,pla9s & develop$ a tribut>y sy/em t excavat$ deeply into ! accumulat$ deposits ne> ! m\nta9 front & c>ri$ away huge volumes ( s$im5t f ! ,great ,pla9s to ,hudson ,bay4 ,by #b million ye>s ago1 ! /reams _h cut d[nw>d to )9 a few hundr$ feet ( _! pres5t level4 ,?is region t has be5 s ?or\ghly dissect$ by ! ,miss\ri ,riv] & its tribut>ies is call$ ! ,miss\ri ,plateau4 ,ab\t #b million ye>s ago1 aft] mu* d[ncutt+ _h already tak5 place & riv] *annels _h be5 firmly e/abli%$1 great ice %eets advanc$ s\?w>d f ,canada into ! ,unit$ ,/ates4 7,see figure #b47 ,^! cont95tal glaci]s =m$1 advanc$1 & retreat$ sev]al times dur+ ! la/ #b million ye>s4 ,at ! nor? & ea/ m>g9s ( ! ,miss\ri ,plateau !y lapp$ onto a high area1 leav+ a mantle ( glacial deposits cov]+ ! b$rock surface & =c+ /reams to adopt new c\rses along ! m>g9 ( ice4 ,! "p ( ! ,miss\ri ,plateau cov]$ by ! cont95tal glaci]s n[ is ref]r$ to z ! ,glaciat$ ,miss\ri ,plateau4 ,s\? ( ! "p once cov]$ by ice is ! ,unglaciat$ ,miss\ri ,plateau4 ,preglacial ,dra9age ,be=e ! initial advance ( ! cont95tal ice %eets1 ! ,miss\ri ,riv] fl[$ nor!a/w>d into ,canada & to ,hudson ,bay4 ,its major tribut>ies1 ! ,yell[/one & ! ,little ,miss\ri jo9$ ! ,miss\ri 9 nor?we/]n ,nor? ,dakota4 ,! ea/-fl[+ ,knife1 ,he>t1 & ,cannonball ,riv]s 9 ,nor? ,dakota also jo9$ a /ream t fl[$ nor?w>d to ,hudson ,bay4 ,glaciat$ ,miss\ri ,plateau ,:5 ! cont95tal ice %eets spread s\?w>d into nor!rn ,montana & ! ,dakotas1 a few isolat$ areas 9 ,montana /ood above ! surr\nd+ pla94 ,^! are mo/ly areas t 7 uplift$ by ! intrusion ( igne\s bodies long be=e ! /reams began d[ncutt+ & c>v+ ! l&4 ,! nor!rnmo/ ( ^! isolat$ m\nta9s1 ! ,sweetgrass ,hills1 7 surr\nd$ by ice & became nunataks1 or isl&s ( l&1 9 ! sea ( advanc+ ice1 :i* pu%$ s\?w>d up aga9/ ! ,highwood ,m\nta9s1 ne> ,great ,falls1 ! ,be>paws s\? ( ,havre1 & ! ,little ,rockies to ! ea/4 ,mu* ( ! nor!rn "p ( ,montana is a pla9 ( little relief t is ! surface ( a ne>ly cont9u\s cov] ( glacial deposits1 g5]ally less ?an #ej feet ?ick4 ,?is pla9 has be5 incis$ by ! ea/-fl[+ po/glacial ,teton1 ,m>ias1 & ,milk ,riv]s4 ,9 ,nor? ,dakota1 a high area on ! ea/ side ( ! ,willi/on bas9 act$ z a b>ri] to ! advance ( ! ice1 mo/ ( :i* 0 div]t$ s\!a/w>d4 ,! m>g9 ( ! ice %eet1 h[ev]1 lapp$ onto ! b$rock high1 :]e x /agnat$4 ,e>li] advances mov$ f>!/ s\?2 ! lat] advances /opp$ nor? ( ! pres5t c\rse ( ! ,miss\ri ,riv]--_! maximum position m>k$ by ridges ( unsort$1 glacially transport$ rock debris 7till7 call$ t]m9al mora9es4 ,nor? ( ! t]m9al mora9es is a di/9ctive l&scape *>act]iz$ by a roll+1 hummocky1 or hilly surface ) ?\s&s ( clos$ depressions betwe5 ! hills & hummocks1 mo/ ( !m occupi$ by lakes4 ,?is is ! deposit left by ! /agnant or dead ice1 & x is call$ dead-ice mora9e4 ,! roll+ upl& 9 ,nor? ,dakota t is cov]$ by dead-ice mora9e & ridges ( t]m9al mora9es f ! la/ glacial advances is call$ ! ,coteau du ,miss\ri 7fig4 #bj74 ,a g5tly slop+ sc>p1 sev]al hundr$ feet high & mo/ly cov]$ by glacial deposits 7ref]r$ to collectively z drift71 sep>ates ! ,coteau du ,miss\ri f ! l[]1 ne>ly flat1 drift-cov]$ pla9s ( ! ,c5tral ,l[l& to ! ea/4 ,?is esc>pm5t1 :i* is call$ ! ,miss\ri esc>pm5t1 is virtually cont9u\s across ! ,/ate ( ,nor? ,dakota s\?w>d into ,s\? ,dakota4 ,! base ( ! ,miss\ri esc>pm5t is ! ea/]n b\nd>y ( ! ,great ,pla9s 9 ^! nor!rn /ates4 ,illu/ration3 ,figure #bj4--;,gr\nd mora9e on ! ,coteau du ,miss\ri1 nor?we/]n ,nor? ,dakota4 ,photograph by ,r4 ,m4 ,l9dvall1 ,u4 ,s4 ,geological ,survey4 ,! advanc+ ice front block$ "o aft] ano!r ( ! nor?w>d-fl[+ /reams ( ! region1 div]t+ !m ea/w>d along ! ice front4 ,%onk9 ,sag1 nor? ( ! ,highwood ,m\nta9s ne> ,great ,falls1 ,mont41 is an ab&on$ div]sion *annel ( ! ,miss\ri ,riv]1 occupi$ :5 ! ice front /ood close to ! nor? slopes ( ! ,highwoods4 ,mu* ( ! pres5t c\rse ( ! ,miss\ri ,riv] f ,great ,falls1 ,mont41 to ,kansas ,city1 ,mo41 0 e/abli%$ z an ice-m>g9al *annel1 & ! ea/-fl[+ "p ( ! ,little ,miss\ri ,riv] 9 ,nor? ,dakota 0 =m$ 9 ! same way4 ,^! valleys 7 cut dur+ ! la/ #b million ye>s4 ,! nor?-fl[+ "p ( ! ,little ,miss\ri ,riv] & ! ea/-fl[+ c\rses ( ! ,knife1 ,he>t1 & ,cannonball ,riv]s 9 ,nor? ,dakota are = ! mo/ "p old]1 preglacial c\rses4 ,! ,little ,miss\ri 0 damm$ by ! ice1 & its wat]s imp\nd$ to =m a huge lake dur+ ! maximum /& ( ! ice1 b ! deposits ( ?is glacial lake are few & make no impr9t on ! l&scape4 ,! valley ( ! ea/-fl[+1 glacially div]t$ "p ( ! ,little ,miss\ri ,riv]1 h[ev]1 is m>k$ly diff]5t f t ( ! nor?-fl[+ preglacial riv]4 ,x is mu* n>r[] & has /eep] walls ?an ! old valley4 ,because x is y\ng]1 x is little modifi$1 except by huge l&slides t h affect$ bo? walls ( ! valley4 ,trem5d\s rotat$ l&slide blocks 9 ! ,nor? ,unit ( ,!odore ,roosevelt ,national ,memorial ,p>k are "s ( ! be/ examples ( ! slump type ( l&slide to be se5 any:]e 7fig4 #ba74 ,melt+ ice at ! front ( ! glaci]s provid$ l>ge volumes ( meltwat] t fl[$ across ! till-mantl$ surface 9 front ( ! glaci] z x melt$ back t[>d ,canada4 ,?is meltwat] took _m c\rses to jo9 ! glacially div]t$ ,miss\ri ,riv]1 & ^! s9u\s meltwat] *annels w9d across ! dead-ice mora9e & ! old]1 less hummocky gr\nd mora9e betwe5 ! ,coteau du ,miss\ri & ! ,miss\ri ,riv]4 ,locally ! s$im5t c>ri$ by ! meltwat] /reams 0 bank$ aga9/ a wall ( ice to =m a small hill ( /ratifi$ drift t is call$ a kame4 ,/reams fl[+ 9 tunnels b5ea? ! ice =m$ s9u\s1 ridgelike deposits call$ esk]s1 & 9 places ! meltwat] deposits =m broad flat areas call$ outwa% pla9s4 ,illu/ration3 ,figure #ba4--,rotat$ slump blocks 9 huge l&slide1 ,nor? ,unit ( ,!odore ,roosevelt ,national ,memorial ,p>k1 ,n4 ,dak4 ,note t lay]+ ( ,=t ,union ,=mation 9 cliffs on skyl9e1 :]e l&slide orig9at$1 is horizontal4 ,?is r limit$ v>iety ( l&=ms1 !n1 *>act]izes ! l&scape ( ! ,glaciat$ ,miss\ri ,plateau4 ,! l&=ms !mselves are te/imony to _! glacial orig9 & to ! great advances ( ! cont95tal ice %eets4 ,?is is a /ream-c>v$ t]ra9 t has be5 modifi$ by cont95tal glaci]s & almo/ completely cov]$ by a ?ick blanket ( glacially transport$ & deposit$ rock debris1 locally hundr$s ( feet ?ick4 ,subsequ5t /ream action has n alt]$ ! l&scape greatly4 ,unglaciat$ ,miss\ri ,plateau ,beyond ! limits rea*$ by ! ice ( ! cont95tal glaci]s1 ! ,unglaciat$ ,miss\ri ,plateau displays ! greate/ v>iety ( l&=ms ( any section ( ! ,great ,pla9s4 ,9 we/]n ,montana1 _m small m\nta9 masses rise above ! g5]al level ( ! plateau1 includ+ ! ,highwood1 ,be>paw1 & ,little ,rocky ,m\nta9s ne> ! m>g9 ( ! glaciat$ area1 & ! ,judi?1 ,big ,sn[y1 ,big ,belt1 ,little ,belt1 ,ca/le1 & ,crazy ,m\nta9s f>!r s\? 7fig4 #bb74 ,_m ( ^!1 su* z ! ,crazy1 ,ca/le1 ,judi?1 & ,big ,sn[y ,m\nta9s1 are areas uplift$ by l>ge1 deeply root$1 intrusive igne\s bodies call$ /ocks1 :i* h be5 expos$ by subsequ5t erosion ( ! ar*$ ov]ly+ s$im5t>y rock lay]s4 ,"s1 su* z ! ,highwood & ,be>paw ,m\nta9s1 are pr$om9antly piles ( lava fl[s1 al?\gh 9 ! ,be>paws ! relat$ intrusive bodies ( igne\s rock =m a "p ( ! m\nta9s4 ,! ,big & ,little ,belt ,m\nta9s 7 =m$ by mu%room-%ap$ intrusive igne\s bodies call$ laccoli?s1 :i* h spread out & dom$ betwe5 lay]s ( s$im5t>y rocks4 ,a numb] ( igne\s bodies also intrude ! rocks ( ! ,miss\ri ,plateau ar\nd ! p]iph]y ( ! ,black ,hills4 ,devils ,t[]1 ! fir/ feature to be designat$ a ,national ,monum5t1 is ! be/ kn[n ( ^! igne\s rock features 7fig4 #bc74 ,illu/ration3 ,figure #bb4--,! ,highwood ,m\nta9s se5 f ! ,little ,belt ,m\nta9s1 ,mont4 ,photograph by ,i4 ,j4 ,witk9d1 ,u4 ,s4 ,geological ,survey4 ,! uplift & volcanism t =m$ ^! m\nta9s took place be=e ! /reams began to cut d[nw>d & segm5t ! ,great ,pla9s4 ,! m\nta9s _h be5 greatly dissect$ be=e ! adv5t ( ! ,great ,ice ,age1 :5 alp9e glaci]s =m$ on ! ,ca/le & ! ,crazy ,m\nta9s & fl[$ d[n "s ( ! /ream-cut valleys4 ,alp9e glacial features su* z cirques1 9 ! high p>ts ( ! m\nta9s1 & glacially modifi$ ,u-%ap$ valleys 7fig4 #bd7 are impressive evid5ce ( ?is glaciation4 ,illu/ration3 ,figure #bc4--;,devils ,t[] ,national ,monum5t1 ,wyo4 ,an igne\s intrusive body expos$ by erosion4 ,photograph by ,f4 ,w4 ,o/]wald1 ,u4 ,s4 ,geological ,survey4 ,! ,miss\ri ,riv] & its tribut>ies--! ,sun1 ,smi?1 ,judi?1 ,mussel%ell1 & ,yell[/one ,riv]s 9 ,montana & ! ,little ,miss\ri ,riv] 9 ,nor? ,dakota--h cut d[n into ! ,miss\ri ,plateau1 cut broad upl& surfaces at _m levels1 & e/abli%$ conf9$ valleys ) valley floors flank$ by t]race remnants ( old] floodpla9s4 ,locally1 high buttes t are remnants ( =m] int]/ream divides rise above ! upl&s4 ,l>ge lakes also 7 =m$ 9 mo/ ( ^! tribut>y valleys because ( damm+ by ! cont95tal ice %eets4 ,illu/ration3 ,figure #bd4--,u-%ap$1 glaciat$ valley ( ,big ,timb] ,creek1 ,crazy ,m\nta9s1 ,mont4 ,photograph by ,w4 ,c4 ,ald51 #aiba1 ,u4 ,s4 ,geological ,survey4 ,we/ ( ! ,black ,hills1 9 ,wyom+1 ! ,tongue ,riv] & ! ,p[d] ,riv] h excavat$ ! ,p[d] ,riv] ,bas9 & produc$ simil> features 7fig4 #be74 ,! ea/-fl[+ tribut>ies ( ! ,miss\ri ,riv]--! ,knife1 ,he>t1 & ,cannonball ,riv]s 9 ,nor? ,dakota & ! ,gr&1 ,moreau1 ,belle ,f\r*e1 ,*ey5ne1 ,bad1 & ,:ite ,riv]s 9 ,s\? ,dakota--simil>ly h %ap$ ! l&scape4 ,mo/ ( ^! riv]s fl[ 9 broad1 old valleys1 e/abli%$ m ?an #b million ye>s ago1 be=e ! fir/ advance ( ! cont95tal ice %eets4 ,"s ( ^! valleys h be5 wid5$ by recession ( ! valley walls by badl& developm5t4 ,badl&s are =m$ by ! cutt+ action ( rivulets & rills fl[+ d[n ov] a /eeply slop+ face ( s(t1 f9e-gra9$ mat]ial compos$ ma9ly ( clay & silt4 ,! intricate c>v+ by ?\s&s ( small /reams ( wat] produces ! di/9ctive r\nd$ & gulli$ t]ra9 we call badl&s4 ,badl&s ,national ,monum5t 9 ,s\? ,dakota 7fig4 #bf7 has be5 e/abli%$ 9 ! rem>kable badl&s t]ra9 cut into ! ,:ite ,riv] ,gr\p along ! nor? valley wall ( ! ,:ite ,riv]1 & ! ,s\? ,unit ( ,!odore ,roosevelt ,national ,memorial ,p>k is 9 ! colorful badl&s ( ! ,little ,miss\ri ,riv]1 =m$ on ! ,=t ,union ,=mation 7fig4 #bg74 ,! ,:ite ,riv] also has cut a /eep sc>p along its s\!rn wall t is call$ ! ,p9e ,ridge esc>pm5t4 ,?is esc>pm5t def9es ! b\nd>y betwe5 ! ,miss\ri ,plateau & ! ,high ,pla9s "h4 ,illu/ration3 ,figure #be4--,view nor!a/ across ! ,deck]s coal m9e & ! ,tongue ,riv] 9 ! ,p[d] ,riv] ,bas91 s\!a/]n ,montana4 ,typical t]ra9 ( unglaciat$ ,miss\ri ,plateau4 ,small mesas ) cliff$ esc>pm5ts on capp+ lay] ( resi/ant s&/one1 su* z ^? 9 ! =egr\nd1 are common4 ,coal m9e is ab\t #a mile across4 ,photograph by ,r4 ,b4 ,taylor1 ,u4 ,s4 ,geological ,survey4 ,! l&scape ( ! ,unglaciat$ ,miss\ri ,plateau has be5 det]m9$ l>gely by ! action ( /reams1 b 9 "s areas igne\s intrusions & volcanoes h produc$ small m\nta9 masses t int]rupt ! pla91 & valley glaci]s h modifi$ ! valleys 9 "s ( ^! m\nta9s4 ,illu/ration3 ,figure #bf4--;,badl&s 9 ,badl&s ,national ,monum5t1 ,s4 ,dak4 ,photograph by ,w4 ,h4 ,raymond1 ,,iii1 ,u4 ,s4 ,geological ,survey4 ,illu/ration3 ,figure #bg4--;,badl&s ( ! ,little ,miss\ri ,riv] 9 ,s\? ,unit ( ,!odore ,roosevelt ,national ,memorial ,p>k1 ,n4 ,dak4 ,view look+ nor?we/ f ,pa9t$ ,canyon ,ov]look along ,int]/ate ,highway #id1 we/ ( ,belfield4 ,,! ,,colorado ,,pi$mont ,! ,colorado ,pi$mont lies at ! ea/]n foot ( ! ,rockies1 7fig4 #a7 l>gely betwe5 ! ,s\? ,platte ,riv] & ! ,arkansas ,riv]4 ,! ,s\? ,platte on ! nor? & ! ,arkansas ,riv] on ! s\?1 aft] leav+ ! m\nta9s1 h excavat$ deeply into ! ,t]ti>y 7#fe- to #b-million-ye>-old7 s$im5t>y rock lay]s ( ! ,great ,pla9s 9 ,colorado & remov$ great volumes ( s$im5t4 ,at ,d5v]1 ! ,s\? ,platte ,riv] has cut d[nw>d #a1ejj to #b1jjj feet to its pres5t level4 ,?ree well-=m$ t]race levels flank ! riv]'s floodpla91 & remnants ( a numb] ( well-=m$ high] l& surfaces are pres]v$ betwe5 ! riv] & ! m\nta9s4 ,along ! we/]n m>g9 ( ! ,colorado ,pi$mont1 ! lay]s ( old] s$im5t>y rock h be5 %>ply upturn$ by ! rise ( ! m\nta9s4 ,! erod$ edges ( ^! upturn$ lay]s h be5 erod$ diff]5tially1 s t ! h>d s&/one & lime/one lay]s =m conspicu\s & cont9u\s hogback ridges 7fig4 #bh74 ,nor? ( ! ,s\? ,platte ,riv]1 ne> ! ,wyom+ bord]1 a sc>p t has be5 cut on ! rocks ( ! ,high ,pla9s m>ks ! nor!rn b\nd>y ( ! ,colorado ,pi$mont4 ,pawnee ,buttes 7fig4 #bi7 are two ( _m butte outli]s ( ! ,high ,pla9s rocks ne> t sc>p1 sep>at$ f ! ,high ,pla9s by erosion z is ,scotts ,bluff1 f>!r nor? 9 ,nebraska4 ,to ! ea/1 ab\t #aj miles nor?we/ ( ,limon1 ,colo41 ,c$> ,po9t =ms a we/-jutt+ pr[ ( ! ,high ,pla9s4 ,! ,arkansas ,riv] simil>ly has excavat$ mu* ( ! ,t]ti>y pi$mont deposits & cut deeply into ! old] ,cretace\s m>9e rocks betwe5 ,canon ,city & ! ,kansas bord]4 ,! upturn$ lay]s along ! m\nta9 front1 m>k$ by hogback ridges & int]v5+ valleys1 cont9ue ne>ly un9t]rupt$ ar\nd ! s\? end ( ! ,front ,range into ! embaym5t 9 ! m\nta9s at ,canon ,city4 ,skyl9e ,drive1 a sc5ic drive at ,canon ,city1 foll[s ! cre/ ( ! ,dakota hogback = a %ort di/ance & provides a f9e panorama ( ! ,canon ,city embaym5t4 ,illu/ration3 ,figure #bh4--;,hogback ridges along ! ,front ,range we/ ( ,d5v]1 ,colo4 ,s\? ,platte ,riv] em]ges f ! m\nta9s & cuts ?r\gh hogbacks 9 middle di/ance4 ,photograph c\rtesy ( ,eug5e ,%e>]1 ,intrase>*1 ,inc4 ,ext5d+ ea/w>d f ! m\nta9 front at ,palm] ,lake1 a high divide sep>ates ! dra9age ( ! ,s\? ,platte ,riv] f t ( ! ,arkansas ,riv]4 ,! cre/ ( ! divide nor? ( ,colorado ,spr+s is g5]ally betwe5 #g1djj & #g1fjj feet 9 altitude1 b ,int]/ate ,highway #be crosses x at ab\t #g1cej feet1 ne>ly #a1ejj feet high] ?an ,colorado ,spr+s & m ?an #b1jjj feet high] ?an ,d5v]4 ,f ! cre/ ( ! divide to nor? ( ,ca/le ,rock1 resi/ant ,oligoc5e ,ca/le ,rock ,conglom]ate 7:i* is equival5t to "p ( ! ,:ite ,riv] ,gr\p ( ! ,high ,pla9s7 is pres]v$ 9 _m places & =ms a protective caprock on mesas & buttes4 ,?is picturesque "p ( ! ,colorado ,pi$mont looks q diff]5t f ! excavat$ valleys ( ! ,s\? ,platte & ,arkansas ,riv]s4 ,mu* ( ! t]ra9 9 ! two riv] valleys has be5 smoo!d by a ne>ly cont9u\s mantle ( w9dbl[n s& & silt4 ,nor?we/]ly w9ds1 :i* frequ5tly bl[ ) ne>-hurricane velocities1 h :ipp$ f9e mat]ial f ! floodpla9s ( ! /reams & spread x ea/w>d & s\!a/w>d ov] mu* ( ! ,colorado ,pi$mont4 ,well-=m$ dunes are n common1 b al9$ g5tle ridges ( s& & silt & abundant %all[ bl[\t depressions in=m u ( ! w9dbl[n orig9 ( ?is cov]4 ,illu/ration3 ,figure #bi4--,pawnee ,buttes 9 nor!a/]n ,colorado4 ,buttes isolat$ by erosion f ,high ,pla9s 9 ! backgr\nd4 ,ogallala ,=mation caps top ( ,buttes4 ,:ite ,riv] ,gr\p =ms l[] "p4 ,! top ( ! highe/ butte is ab\t #bdj feet above ! saddle betwe5 ! two buttes4 ,photograph by ,r4 ,d4 ,mill]1 ,u4 ,s4 ,geological ,survey4 ,9 ! ,colorado ,pi$mont1 !n1 ! erosional effects ( /reams are ! mo/ conspicu\s features ( ! l&scape1 b ^! are enhanc$ by ! /eep tilt+ ( ! lay]$ rocks along ! we/]n m>g9 z a result ( e>? movem5t & modifi$ by ! ne>ly ubiquit\s products ( w9d action1 :i* h s(t5$ ! l&scape ) a widespread cov] ( w9dbl[n s& & silt4 ,,pecos ,,valley ,s\? ( ! l& ( volcanic rocks t is ! ,raton section1 ! ,pecos ,riv] has cut a broad valley f ! ,sangre de ,cri/o ,m\nta9s1 9 ,new ,mexico1 s\?w>d to ! ,rio ,gr&e1 & has remov$ ! pi$mont cov] ( ,ogallala ,=mation & cut deeply into ! und]ly+ rocks4 ,! ,ogallala ,=mation capp+ ! ,high ,pla9s to ! ea/ =ms a rimrock at ! top ( ! %>p ,mescal]o esc>pm5t1 :i* is ! ea/]n b\nd>y ( ! ,pecos ,valley4 7,see figure #d47 ,! we/]n b\nd>y ( ! ,pecos ,valley is ! ea/]n base ( discont9u\s m\nta9 ranges4 ,! great ?ickness ( ,t]ti>y deposits t =m$ on ! nor!rn ,great ,pla9s did n accumulate "h1 & ! ,pecos ,riv] has cut its valley into ! old] m>9e s$im5t>y rocks4 ,! rocks und]ly+ ! surface ( mu* ( ! ,pecos ,valley are upp] ,paleozoic lime/ones4 ,! soluble nature ( lime/one is responsible = "s ( ! mo/ spectacul> features ( ! l&scape 9 ! ,pecos ,valley4 ,= ab\t #aj miles nor? & #ej miles s\? ( ,vaughn1 ,n4 ,mex41 collaps$ solution cav]ns 9 upp] ,paleozoic lime/ones h produc$ an unusual type ( topography call$ k>/4 ,k>/ topography is typifi$ by num]\s closely spac$ s9ks or clos$ depressions1 "s ( :i* are v deep holes1 caus$ by ! collapse ( ! ro( ( a cave or solution cavity into ! und]gr\nd void1 leav+ hills1 sp9es1 or hummocks at ! top ( ! int]v5+ walls or ribs sep>at+ ! depressions4 ,al?\gh ! k>/ 9 ! vic9ity ( ,vaughn is p]haps ! mo/ conspicu\s solution ph5om5on1 s9ks & caves are common ?r\gh\t ! ,pecos ,valley4 ,at ,bottomless ,lakes ,/ate ,p>k ea/ ( ,roswell1 ,n4 ,mex41 sev5 lakes occupy l>ge s9kholes caus$ by ! solution ( salt & gypsum 9 und]ly+ rocks4 ,! mo/ spectacul> example ( solution ( lime/one by gr\nd wat] is ,c>lsbad ,cav]ns1 ,n4 ,mex41 "o ( ! mo/ beautiful caves 9 ! _w4 ,?is celebrat$ solution cavity is pres]v$ 9 a national p>k4 ,! ,pecos ,riv] along mu* ( its pres5t c\rse fl[s 9 a v]tical-wall$ canyon ) lime/one rims4 ,! ,canadian ,riv]1 fl[+ ea/w>d f ! ,sangre de ,cri/o ,m\nta9s1 has cut a deep canyon along ! nor!rn "p ( ! ,pecos ,valley section4 ,! %>p rims ( ! ,dakota ,s&/one at ! ,canadian esc>pm5t1 nor? ( ! ,canadian ,riv]1 =m ! nor!rn b\nd>y ( ! ,pecos ,valley section4 ,! %>p1 nor!a/-tr5d+ brok5 flexure call$ ! ,bord] ,hills t is cross$ by ,u4 ,s4 ,highway #gj-chj ab\t #bj miles we/ ( ,roswell is a unique l&=m ( ! ,pecos ,valley4 ,?is m>k$ly l9e> upfold$ 7anticl9al7 /ructure =ms a ridge m ?an #cj miles long & ab\t #bjj feet high4 ,z 9 ! ,colorado ,plateau1 w9dbl[n s& & silt mantle ! l&scape 9 _m places1 b ! greate/ accumulations are along ! base ( ! ,mescal]o esc>pm5t at ! nor!a/ & s\!a/ corn]s ( ! ,pecos ,valley section4 ,ea/ ( ! ,pecos ,riv]1 9 ! s\!a/ "p ( ! ,pecos ,valley1 ! und]ly+ rocks h yield$ mu* oil & pota%4 ,oil fields are common ea/ ( ,artesia & ,c>lsbad1 & pota% is m9$ ea/ ( ,c>lsbad4 ,! ,pecos & ,canadian ,riv]s & _! tribut>ies h creat$ ! g5]al outl9e ( ! l&scape ( ! ,pecos ,valley1 b und]gr\nd solution ( lime/one by gr\nd wat] & ! collapse ( ro(s ( ^! cavities h contribut$ mu* detail to ! surface t *>act]izes ! ,pecos ,valley today4 ,,edw>ds ,,plateau ,s\? ( ! ,pecos ,valley section1 ! ,pecos ,riv] cont9ues its j\rney to ! ,rio ,gr&e 9 a /eep-wall$ canyon cut #djj to #ejj feet bel[ ! level ( a plateau surface ( ,cretace\s lime/one f :i* little has be5 /ripp$ except a ?9 ,t]ti>y cov] ( ,ogallala ,=mation 7fig4 #cj74 ,to ! ea/1 ! plateau has be5 simil>ly incis$ by ! ,devils ,riv] & ! ,we/ ,nueces & ,nueces ,riv]s4 ,ea/ ( ! ,nueces to ! esc>pm5t =m$ by ! ,balcones fault zone1 ! s\!rn "p ( ! ,edw>ds ,plateau has be5 intricately dissect$ by ! ,frio1 ,sab9al1 ,m$9a1 ,guadalupe1 & ,p$]nales ,riv]s & _! tribut>y sy/ems4 ,san ,antonio & ,au/91 ,tex41 are locat$ on ! ,coa/al ,pla9 at ! edge ( ! ,balcones fault zone4 ,illu/ration3 ,figure #cj4--,rio ,gr&e & ! flat-ly+ lime/one lay]s ( ! ,edw>ds ,plateau d[n/ream f ! m\? ( ! ,pecos ,riv]4 ,mexico on ! left side ( picture4 ,photograph by ,v4 ,l4 ,freeman1 ,u4 ,s4 ,geological ,survey4 ,! ,pecos ,riv]1 & to a less] ext5t ! ,devils & ,nueces ,riv]s1 p>ticul>ly 9 _! l[] c\rses1 h entr5*$ !mselves deeply 9 ! plateau 9 rem>kable me&]+ c\rses ( a type t is usually f\nd only 9 broad1 l[-ly+ floodpla9s4 ,^! /ream c\rses reflect ! /ream environm5t prior to regional uplift4 ,s9kholes pit ! relatively undissect$ lime/one plateau surface 9 ! nor!a/ "p ( ! ,edw>ds ,plateau1 & "s und]gr\nd solution cavities 9 ! lime/one are well-kn[n caves1 su* z ! ,cav]ns ( ,sonora1 s\?we/ ( ,sonora1 ,tex4 ,oil & gas fields are widely develop$ 9 ! nor!rn "p ( ! ,edw>ds ,plateau1 b only cattle ran*es are f\nd 9 ! b>e s\!rn "p4 ,anci5t oceans deposit$ ! lime/ones t n[ cap ! ,edw>ds ,plateau2 /reams plan$ (f ! surface ( ! flat-ly+ lime/one lay]s & entr5*$ !mselves 9 /eep-wall$ valleys2 & gr\nd wat] dissolv$ ! lime/one & creat$ ! solution cavities t are ! caves & s9ks ( ! ,edw>ds ,plateau4 ,wat] has creat$ ?is l&scape4 ,,pla9s ,,bord] ,,section ,! ,miss\ri ,plateau1 ! ,colorado ,pi$mont1 ! ,pecos ,valley1 & ! ,edw>ds ,plateau all 7 outl9$ by /reams t fl[$ f ! m\nta9s4 ,on ! ea/]n bord] ( ! ,great ,pla9s1 h[ev]1 headw>d cutt+ by /reams t h _! s\rce areas 9 ! ,high ,pla9s has dissect$ a l>ge area1 ma9ly 9 ,kansas4 ,?is ,pla9s ,bord] ,section comprises a numb] ( ea/-tr5d+ riv] valleys--( ! ,republican1 ,solomon1 ,sal9e1 ,smoky ,hill1 ,arkansas1 ,m$ic9e ,lodge1 ,cim>ron1 & ,nor? ,canadian ,riv]s--& int]/ream divides1 mo/ ( :i* are intricately dissect$4 ,nor? ( ! ,arkansas ,riv]1 ! ea/-fl[+ ,republican1 ,solomon1 ,sal9e1 & ,smoky ,hill ,riv]s h incis$ !mselves a few hundr$ feet bel[ ! ,t]ti>y ,high ,pla9s surface & h develop$ sy/ems ( closely spac$ tribut>y draws4 ,! int]/ream divides are n>r[1 & ! tribut>y heads ne>ly meet at ! divides4 ,?is intricately dissect$ "p ( ! ,pla9s ,bord] section is call$ ! ,smoky ,hills4 ,"s isolat$ buttes ( ,cretace\s rocks left 9 ! upp] valley ( ! ,smoky ,hill ,riv] are call$ ! ,monum5t ,rocks4 ,a l>ge area ( r\nd$ b\ld]s expos$ by erosion s\? ( ! ,solomon ,riv]1 s\?we/ ( ,m9neapolis1 ,kans41 is call$ 8,rock ,city40 ,^! b\ld]s orig9at$ z resi/ant nodules 7concretions7 )9 ! ,cretace\s rocks t conta9$ !m4 ,s\? ( ! ,arkansas ,riv] is a broad1 ne>ly flat upl& sometimes ref]r$ to z ! ,great ,b5d ,pla9s4 ,! ,m$ic9e ,lodge ,riv] has cut headw>d into ! s\!a/]n "p ( ! ,great ,b5d ,pla9s & creat$ a ?or\ghly dissect$ topography 9 ,triassic r$ rocks t is locally call$ ! ,r$ ,hills4 ,9 a few places1 badl&s h =m$ 9 ! ,r$ ,hills4 ,"s l>ge s9ks or collapse depressions h =m$ because ( solution ( salt & gypsum at dep? by gr\nd wat]4 ,big & ,little ,bas9s1 9 ,cl>k ,c\nty 9 s\?-c5tral ,kansas1 7 =m$ 9 ?is way4 ,s& dunes h accumulat$ 9 places1 especially ne> /ream valleys4 ,dunes are common1 = example1 along ! nor? side ( ! ,nor? ,canadian ,riv]4 ,oil & gas fields are widely develop$ 9 ! s\!a/ "p ( ! ,pla9s ,bord] section--9 ! ,smoky ,hills1 ! ,great ,b5d ,pla9s1 & ! ,r$ ,hills4 ,! ,pla9s ,bord] section1 l ! ,miss\ri ,plateau1 ! ,colorado ,pi$mont1 & ! ,pecos ,valley1 is prim>ily a product ( /ream dissection4 ,! diff]5ces 9 ! out/&+ l&=ms ( ! section are ma9ly ! result ( diff]5ces 9 ! h>dness ( ! erod$ rocks4 ,,epilogue ,! ,great ,pla9s1 z we h se51 is _m ?+s4 ,x conta9s ?ick lay]s ( rock t =m$ 9 oceans1 & y\ng] lay]s ( rocks deposit$ by /reams4 ,^! rocks h be5 affect$ by e>? movem5ts & inject$ by hot molt5 rock1 "s ( :i* rea*$ ! surface z volcanic rock4 ,! rocks h be5 c>v$ by /reams1 dissolv$ by gr\nd wat]1 p>tly cov]$ by glaci]s1 & bl[n by w9ds4 ,all ( ^! ag5ts h play$ important roles 9 det]m9+ ! l&scape & ! l&=ms ( ! ,great ,pla9s4 ,b ! /reams 7 ! ma/] ag5t4 ,!y =m$ ! great depositional pla9 t 0 to become ! ,great ,pla9s1 & !n began to de/roy x--leav+ only ! ,high ,pla9s to rem9d u ( :at x 04 ,^? long miles we travel across ! ,high ,pla9s are a j\rney ?r\gh hi/ory--geologic hi/ory4 ,,ackn[l$gm5ts ,?is n>rative hi/ory ( geologic & biologic ev5ts 9 ! ,great ,pla9s _h its orig9 9 a /udy int5d$ to id5tify pot5tial ,national ,natural ,l&m>ks 9 ! ,great ,pla9s1 commission$ by ! ,national ,p>k ,s]vice4 ,william ,a4 ,cobban1 ,g4 ,edw>d ,lewis1 & ,reub5 ,j4 ,ross ( ! ,u4 ,s4 ,geological ,survey 7 collaborators 9 t /udy1 & "s ( _! contributions to ! hi/ory ( life on ! ,great ,pla9s h be5 incorporat$ into ?is n>rative1 :i* 0 und]tak5 at ! urg+ ( ,wallace ,r4 ,hans54 ,! photographic illu/rations1 o!r ?an ^? obta9$ f ! film libr>y ( ! ,u4 ,s4 ,geological ,survey1 7 provid$ by ! int]e/ & ef=t ( my fri5ds & colleagues ( ! ,geological ,survey--includ+ ,c4 ,r4 ,dunrud1 ,v4 ,l4 ,freeman1 ,c4 ,d4 ,mill]1 ,r4 ,d4 ,mill]1 ,f4 ,w4 ,o/]wald1 ,r4 ,l4 ,p>k]1 ,w4 ,h4 ,raymond1 ,,iii1 ,k5ne? ,%av]1 & ,r4 ,b4 ,taylor--& by ,eug5e ,%e>]1 ,intrase>*1 ,inc41 ,d5v]1 ,colo4 ,)\t _! help ?is publication w\ld n h be5 possible4 ,,"s ,,s\rce ,,ref]5ces ,ald51 ,w4 ,c41 #aicb1 ,physiography & glacial geology ( ea/]n ,montana & adjac5t areas3 ,u4 ,s4 ,geological ,survey ,pr(essional ,pap] #agd1 #acc p4 ,bluemle1 ,j4 ,p41 #aigg1 ,! face ( ,nor? ,dakota--! geologic /ory3 ,nor? ,dakota ,geological ,survey ,education ,s]ies #aa1 #gc p4 ,colton1 ,r4 ,b41 ,lemke1 ,r4 ,w41 & ,l9dvall1 ,r4 ,m41 #aifa1 ,glacial map ( ,montana ea/ ( ! ,rocky ,m\nta9s3 ,u4 ,s4 ,geological ,survey ,miscellane\s ,geologic ,inve/igations ,map ,i-#cbg4 ,colton1 ,r4 ,b41 ,lemke1 ,r4 ,w41 & ,l9dvall1 ,r4 ,m41 #aifc1 ,prelim9>y glacial map ( ,nor? ,dakota3 ,u4 ,s4 ,geological ,survey ,miscellane\s ,geologic ,inve/igations ,map ,i-#cca4 ,curtis1 ,b4 ,f41 ed41 #aige1 ,c5ozoic hi/ory ( ! s\!rn ,rocky ,m\nta9s--,pap]s d]iv+ f a symposium pres5t$ at ! ,rocky ,m\nta9 ,section meet+ ( ! ,geological ,society ( ,am]ica1 ,b\ld]1 ,colorado1 #aigc3 ,geological ,society ( ,am]ica ,memoir #add1 #bgi p4 ,d>ton1 ,n4 ,h41 #aije1 ,prelim9>y report on ! geology & und]gr\nd wat] res\rces ( ! c5tral ,great ,pla9s3 ,u4 ,s4 ,geological ,survey ,pr(essional ,pap] #cb1 #dcc p4 ,fl9t1 ,r4 ,f41 #aiee1 ,plei/oc5e geology ( ea/]n ,s\? ,dakota3 ,u4 ,s4 ,geological ,survey ,pr(essional ,pap] #bfb1 #agc p4 ,frye1 ,j4 ,c41 & ,leon>d1 ,a4 ,b41 #aife1 ,quat]n>y ( ! s\!rn ,great ,pla9s1 9 ,wright1 ,h4 ,e41 ,jr41 & ,frey1 ,d4 ,g41 eds41 ,! ,quat]n>y ( ! ,unit$ ,/ates--,a review volume = ! #g? ,congress ( ! ,int]national ,association = ,quat]n>y ,rese>*3 ,pr9ceton ,univ]sity ,press1 p4 #bjc-baf4 ,h[>d1 ,a4 ,d41 #aieh1 ,dra9age evolution 9 nor!a/]n ,montana & nor?we/]n ,nor? ,dakota3 ,geological ,society ( ,am]ica ,bullet91 v4 #fi1 no4 #e1 p4 #ege-ehh4 ,johnson1 ,r4 ,b41 #aifa1 ,patt]ns & orig9 ( radial dike sw>ms associat$ ) ,we/ ,spani% ,peak & ,dike ,m\nta91 s\?-c5tral ,colorado3 ,geological ,society ( ,am]ica ,bullet91 v4 #gb1 no4 #d1 p4 #egi-eij4 ,judson1 ,s4 ,s41 ,jr41 #aiej1 ,depressions ( ! nor!rn portion ( ! s\!rn ,high ,pla9s ( ea/]n ,new ,mexico3 ,geological ,society ( ,am]ica ,bullet91 v4 #fa1 no4 #c1 p4 #bec-bgd4 ,kee*1 ,c4 ,f41 & ,b5tall1 ,ray1 #aiga1 ,dunes on ! pla9s--,! ,s& ,hills region ( ,nebraska3 ,nebraska ,univ]sity ,cons]vation & ,survey ,division ,res\rces ,report #d1 #ah p4 ,lemke1 ,r4 ,w41 ,laird1 ,w4 ,m41 ,tipton1 ,m4 ,j41 & ,l9dvall1 ,r4 ,m41 #aife1 ,quat]n>y geology ( nor!rn ,great ,pla9s1 9 ,wright1 ,h4 ,e41 ,jr41 & ,frey1 ,d4 ,g41 eds41 ,! ,quat]n>y ( ! ,unit$ ,/ates--,a review volume = ! #g? ,congress ( ! ,int]national ,association = ,quat]n>y ,rese>*3 ,pr9ceton ,univ]sity ,press1 p4 #ae-bg4 ,mansfield1 ,g4 ,r41 #aijg1 ,glaciation 9 ! ,crazy ,m\nta9s ( ,montana3 ,geological ,society ( ,am]ica ,bullet91 v4 #ai1 p4 #eeh-efg4 ,pettyjohn1 ,w4 ,a41 #aiff1 ,eoc5e paleosol 9 ! nor!rn ,great ,pla9s1 9 ,geological ,survey rese>* #aiff3 ,u4 ,s4 ,geological ,survey ,pr(essional ,pap] #eej-;,c1 p4 ,c#fa-;,c#fe4 ,rob9son1 ,c4 ,s41 #aief1 ,geology ( ,devils ,t[] ,national ,monum5t1 ,wyom+3 ,u4 ,s4 ,geological ,survey ,bullet9 #ajba-;,i1 p4 #bhi-cjb4 ,smi?1 ,h4 ,t4 ,u41 #aife1 ,dune morphology & *ronology 9 c5tral & we/]n ,nebraska3 ,j\rnal ( ,geology1 v4 #gc1 no4 #d1 p4 #eeg-egh4 ,/orm]1 ,j4 ,c41 ,jr41 #aigb1 ,ages & nature ( volcanic activity on ! s\!rn ,high ,pla9s1 ,new ,mexico & ,colorado3 ,geological ,society ( ,am]ica ,bullet91 v4 #hc1 no4 #h1 p4 #bddc-bddh4 ,/rahl]1 ,a4 ,n41 & ,/rahl]1 ,a4 ,h41 #aigh1 ,mod]n physical geography3 ,new ,york1 ,john ,wiley ,sons1 #ejb p4 ,?ornbury1 ,w4 ,d41 #aife1 ,regional geomorphology ( ! ,unit$ ,/ates3 ,new ,york1 ,john ,wiley1 #fji p4 ,wright1 ,h4 ,e41 ,jr41 #aigj1 ,vegetational hi/ory ( ! ,c5tral ,pla9s1 9 ,plei/oc5e & rec5t environm5ts ( ! c5tral ,great ,pla9s3 ,kansas ,univ]sity ,dep>tm5t ( ,geology ,special ,publication #c1 p4 #aeg-agb4 ,,index ,italic page numb]s indicate major ref]5ces ,a ,page ,ackn[l$gm5ts #di ,agriculture #cj ,alaska #aa ,anad>ko bas9 #aa1 #af ,arik>ee ,=mation #ah ,arkansas ,riv] #b1 #g1 #bc1 #be1 #bi1 #cj1 #db1 #dc1 #dd1 #dh ,artesia1 ,n4 ,mex4 #df ,au/91 ,tex4 #dg ,b ,bad ,riv] #ci ,badl& developm5t #ci ,badl&s ,national ,monum5t #ci ,balcones fault zone #bc1 #df ,basalt fl[s #bj1 #bd ,be>paw ,m\nta9s #cc1 #cf ,belle ,f\r*e ,riv] #ci ,b5ts ,=t1 ,colo4 #b ,big ,bas91 ,kans4 #dh ,big ,belt ,m\nta9s #cf ,big ,sn[y ,m\nta9s #cf ,bison #a ,black ,hills #g1 #aa1 #ah1 #ai1 #bj1 #cg ,bord] ,hills #df ,bottomless ,lakes1 ,n4 ,mex4 #de ,brazos ,riv] #bc ,burnet1 ,tex4 #bc ,c ,camels #af1 #ah ,canada #a1 #e1 #cc ,canadian esc>pm5t #bc1 #df ,canadian ,riv] #bc1 #bi1 #cj1 #df ,cannonball ,riv] #cc1 #ce1 #ci ,canon ,city1 ,colo4 #dc ,caprock esc>pm5t #g1 #bi ,capul9 ,m\nta9 #bj1 #bc ,c>lsbad1 ,n4 ,mex4 #df ,c>lsbad ,cav]ns1 ,n4 ,mex4 #de ,c>rizo ,creek #be ,ca/le ,m\nta9s #cg ,ca/le ,rock1 ,colo4 #dc ,ca/le ,rock ,conglom]ate #dc ,cav]ns ( ,sonora #dg ,c$> ,po9t #dc ,c5tral ,l[l& #e1 #cd ,c5tral ,texas ,uplift #g1 #ai1 #bj1 #bb ,*ey5ne1 ,wyo4 #bg ,*ey5ne ,riv] #ci ,cim>ron ,riv] #dh ,cirques #ch ,cl>k ,c\nty1 ,kans4 #dh ,climate #b ,coal #af ,coa/al ,pla9 #e1 #g1 #aj1 #dg ,colorado #ai ,colorado ,pi$mont #g1 #aj1 #ai1 #bc1 #db1 #dh1 #di ,colorado ,plateau #df ,colorado ,riv] #bc ,colorado ,spr+s1 ,colo4 #dc ,coteau du ,miss\ri #cd1 #ce ,crazy ,m\nta9s #cg ,creosote #a ,cretace\s ,p]iod #aa1 #af1 #ai1 #bd1 #dc1 #df1 #dh ,d ,dakota hogback #dc ,dakota ,s&/one #bb1 #bc1 #bd1 #df ,dawson ,=mation #af ,dead-ice mora9es #cd ,def9ition #a ,de=mation #aa ,d5v]1 ,colo4 #db ,d5v] ,=mation #af ,deposition #aj1 #aa1 #cb1 #dd ,devils ,riv] #df ,devils ,t[]1 ,wyo4 #cg ,diff]5tial erosion #bc1 #be1 #db ,dikes #be ,d9osaurs #af ,drift #cd ,e ,edw>ds ,plateau #aj1 #ai1 #bi1 #df1 #dh ,eoc5e ,epo* #af ,epilogue #di ,erosion #ah ,esc>pm5ts #d1 #g1 #bc1 #cd ,esk]s #ce ,f ,f>m+ #cj ,fi%]s ,peak #bc ,fissures #bj ,=e/s #a1 #b1 #g ,=t ,union ,=mation #af1 #dj ,fossils #af ,frio ,riv] #df ,front ,range #dc ,g ,gangplank #bg ,gas #cj1 #dg1 #di ,glaciation #b1 #e1 #aa1 #cc ,gr& ,riv] #ci ,great ,b5d1 ,kans4 #b ,great ,b5d ,pla9s #dh1 #di ,great ,falls1 ,mont4 #cc1 #ce ,great ,ice ,age #e ,great ,lakes #e ,guadalupe ,riv] #df ,gulf ,coa/al ,pla9 #g ,h ,h>ney ,peak #bj ,havre1 ,mont4 #cc ,he>t ,riv] #cc1 #ce1 #ci ,hell ,creek ,=mation #aa ,high ,pla9s #g1 #aj1 #be1 #de1 #dh ,highwood ,m\nta9s #cc1 #ce1 #cf ,horses #af1 #ah ,hudson ,bay #cb1 #cc ,i ,ice ,age #e ,indep5d5ce1 ,mo4 #b ,int]ior ,highl&s #e ,int]ior ,pla9s #e1 #aa ,int]/ate ,highway #be #dc ,int]/ate ,highway #gj #d ,introduction #a ,j ,jewel ,cave #ba ,jo9ts #bj ,judi? ,m\nta9s #cf ,judi? ,riv] #ch ,junip] #a ,k ,kames #ce ,kansas #aj1 #dh ,kansas ,city1 ,mo4 #ce ,k>/ topography #de ,ke>ney1 ,nebr4 #b ,k+ ,m\nta9 #bi ,knife ,riv] #cc1 #ce1 #ci ,l ,laccoli?s #cg ,lake developm5t #cd1 #ci ,lance ,=mation #aa ,l>amie ,=mation #af ,lava fl[s #cg ,lewis & ,cl>k exp$ition #b ,lime/one ,plateau #ba1 #bb ,limon1 ,colo4 #d1 #dc ,little ,bas91 ,kans4 #dh ,little ,belt ,m\nta9s #cf ,little ,miss\ri ,riv] #cc1 #ce1 #ch1 #dj ,little ,rocky ,m\nta9s #cc1 #cf ,littlefield1 ,tex4 #cj ,llano ,e/acado #bi1 #cj ,loess #bi ,longhorn ,cav]ns #bc ,m ,m>ias ,riv] #cc ,mc,camey1 ,tex4 #bi ,m$ic9e ,lodge ,riv] #dh ,m$9a ,riv] #df ,mesa de ,maya #bj1 #bd1 #be ,mescal]o esc>pm5t #g1 #bi1 #de1 #df ,mesquite #a ,mexico #a1 #aa ,milk ,riv] #cc ,m9neapolis1 ,kans4 #dh ,mioc5e ,epo* #bc ,miss\ri esc>pm5t #cd ,miss\ri ,plateau #g1 #ai1 #bj1 #cb1 #dh1 #di ,miss\ri ,riv] #e1 #g1 #be1 #cb1 #cc1 #ce1 #ch ,montana #cc ,monum5t ,rocks #dh ,mora9es #cd ,moreau ,riv] #ci ,moropus #ah ,m\nt ,ru%more #bj ,mussel%ell ,riv] #ch ,n ,nebraska #g1 #bi ,nebraska ,s& ,hills #bi ,ne$les area1 ,black ,hills #bj ,new ,mexico #g1 #ai1 #de ,nor? ,canadian ,riv] #dh1 #di ,nor? ,dakota #cc1 #cd1 #ce ,nueces ,riv] #df ,nunataks #cc ,o ,oak trees #a ,odessa1 ,tex4 #cj ,ogallala ,=mation #ah1 #bc1 #bd1 #be1 #bg1 #bi1 #de1 #df ,ohio ,riv] #e ,oil #cj1 #df1 #dg1 #di ,oklahoma #g ,oligoc5e ,epo* #af1 #dc ,oregon ,trail #b ,oua*ita prov9ce #e ,outwa% pla9s #ce ,oz>k ,plateaus #e ,p ,paleoc5e ,epo* #af1 #bc ,paleozoic ,era #ba1 #cj1 #de ,palm] ,lake #dc ,pampa1 ,tex4 #cj ,pawnee ,buttes #db ,pecos ,riv] #g1 #be1 #de1 #df ,pecos ,valley #g1 #aj1 #ai1 #bc1 #de1 #dh1 #di ,p$]nales ,riv] #dg ,pike1 ,zebulon iii1 #b ,p9e ,ridge esc>pm5t #g1 #bi1 #dj ,pione]s #b ,pla9s ,bord] ,section #ai1 #dh ,platte ,riv] #b1 #be1 #bi ,plei/oc5e ,epo* #e ,poison ,canyon ,=mation #af1 #bc1 #bd ,p[d] ,riv] #ci ,p[d] ,riv] ,bas9 #ci ,purgatoire ,=mation #bd ,purgatoire ,riv] #be ,r ,racetrack1 ,! #bb ,ra9fall #b ,rapid ,city1 ,s4 ,dak4 #bj ,raton ,bas9 #bd ,raton ,=mation #af ,raton ,mesa #bj1 #bc ,raton section #aj1 #bj1 #bc1 #de ,r$ ,hills #dh1 #di ,r$ ,valley #bb ,republican ,riv] #d1 #bi1 #dh ,rh9oc]oses #af1 #ah ,rio ,gr&e #g1 #de ,rocky ,m\nta9s #e1 #ai ,roswell1 ,n4 ,mex4 #de ,s ,sab9al ,riv] #df ,sal9a1 ,kans4 #d ,sal9e ,riv] #d1 #dh ,san ,antonio1 ,tex4 #dg ,s& dunes #dd1 #di ,s& ,hills1 ,nebr4 #bi ,sangre de ,cri/o ,m\nta9s #g1 #de1 #df ,scotts ,bluff ,national ,monum5t #bg1 #db ,s$im5tation #aj1 #aa1 #cb ,%onk9 ,sag #ce ,s9kholes #dg1 #dh ,skyl9e ,drive1 ,canon ,city1 ,colo4 #dc ,smi? ,riv] #ch ,smoky ,hill ,riv] #d1 #dh ,smoky ,hills #dh1 #di ,soil developm5t #af ,solomon ,riv] #d1 #dh ,solution cavities #de1 #dg1 #dh ,sonora1 ,tex4 #dg ,s\? ,dakota #bj1 #bi1 #cc1 #cd ,s\? ,dakota ,badl&s #af ,s\? ,platte ,riv] #d1 #g1 #db1 #dc1 #dd ,spani% ,peaks #ai1 #bd ,spruce trees #b ,/ream deposition #aa1 #cb ,summ>y #di ,sun ,riv] #ch ,sup]ior ,upl& #e1 #aj ,sweetgrass ,hills #cc ,sylvan ,lake #bj ,t ,tapirs #af ,t]ti>y ,p]iod #db1 #dc1 #de1 #df1 #dh ,teton ,riv] #cc ,texas #g ,!odore ,roosevelt ,national ,memorial ,p>k #ce1 #dj ,till #cd ,titano!res #af ,tongue ,riv] #ci ,trails #b ,trees #a1 #b1 #g ,triassic ,p]iod #ba ,tric]atops #af ,tr9idad1 ,colo4 #be ,u ,uplift #aa1 #af1 #ai1 #cb1 #cg ,v ,valley developm5t #ci ,vaughn1 ,n4 ,mex4 #de ,vegetation #a1 #b1 #g1 #aj1 #af ,v]mejo ,=mation #af ,volcanoes #af1 #bj1 #dj ,w ,wals5burg1 ,colo4 #bd ,w>p+ #aa ,well-drill+ #aa ,we/ ,nueces ,riv] #df ,:ite ,riv] #bi1 #ci1 #dj ,:ite ,riv] ,gr\p #af1 #dj1 #dd ,willi/on bas9 #aa1 #af1 #cc ,w9d ,cave #ba ,w9d deposition #dd ,wyom+ #bj1 #ci ,y ,yell[/one ,riv] #cc1 #ch ,illu/ration3 ,u4 ,s4 ,,dep>tm5t ,,( ,,! ,,int]ior ,m>* #c1 #ahdi ,transcrib]'s ,notes --,reta9$ publication in=mation f ! pr9t$ edition3 ?is e,book is public-doma9 9 ! c\ntry ( publication4 --,9 ! text v]sions only1 text 9 italics is delimit$ by und]scores4