FIGURE 1.1: Above Timberline, By R. E. DeCamp, 1928

ulaword “Cenozoic” means “recent life.” This era introducedthe first mammals and the first human beings. It was alsothe mostoula is probablyGlacial Lake Missthe time of the Ice Ages.n changeof how glaciers cadramatic exampleethssWhen the Cenozoic era began, the land dried up androace formed a damthe landscape. Icedat backbecame more desert-like. Volcanoes still were quite activeColumbia River thClark Fork of thernsteweofsacross the West.eams and riverup most of the str-foot001,0adteeacrThen, about 2 million years ago, the climate cooledtersMontana. These wasquare miles. Its003,0drevecoandgrew wetter, producing heavy rains and snowfall.atdeep lake th50 feet above4,2erovstjuswaTemperatures dropped by only a few degrees, but it washighest shorelineenough that the snow and ice accumulated faster than itsea level.ased am broke, it releWhen the ice damelted, creating glaciers (masses or slow-moving riversmiles ofIt shot 500 cubiccatastrophic flood.abimluof ice) that advanced across the land.Coark Fork and thewater down the ClrnsteeaGlaciers act like bulldozers. They force everything ing the scablands ofRiver gorge, carvinicenscethteeafront of them upward and out to the edges, pushinglping to crWashington and heical evogolGee.rgGoabirock and earth into new shapes. In Montana, glacierslumcanyons of the Coke Missoula filledLaialacGlatthspushed around piles of rock and earth, large boulders,idence showic style at leastphtrotascaachsuand even entire ridges. They formed ice dams thatand emptied inars.ye001,0erovescreated huge lakes and forced rivers to find new outlets36 timto the sea.Imagine a wall of ice more than two miles deep, stretching along thecurrent course of the Missouri River from the Rocky Mountains eastFIGURE 1.7: Global warming has shrunktoward North Dakota. This ice sheet weighed down the surface of themany of the world’s glaciers. In 1850land itself.Glacier National Park had about 150glaciers; in 2007 there were only 37.At least four times, glaciers moved into northern Montana, pushingThis 1930s photo shows an ice cave inrocks and sediment to form U-shaped mountain valleys, and then leavthe Boulder Glacier in Glacier Nationaling lakes and rivers behind when they receded during warmer periods.Park. Today a person standing where thesepeople stood would see only bare ground.These glaciers formed much of Montana’s valley geography.After the last Ice Age (which occurred between 10,000 and 13,000years ago), the climate warmedagain. The lush foliage that hadsupported the megafauna (largeanimals) dried up and became desert or grasslands. The world beganto look more like it does today.Most of the prehistoric mammals—includingmastodons,wooly mammoths, saber-toothedtigers, and the giant beaver—either adapted (changed to meetthe requirements of their new environment) or became extinct. Theenormous wooly mammoths andmastodons became extinct. Thelarge short-faced bear and direwolf evolved into their smallerGlacial Lake Misso8PART 1: BAC K THROUGH TIME

modern cousins, the grizzly and thetimber wolf. Some animals, like horsesand tapirs, became extinct in NorthAmerica but survived elsewhere.The new climate, with its ownset of weather patterns and vegetation, encouraged the developmentof mammals that we know: bison,elk, deer, bears, bighorn sheep, coyotes, skunks, and rabbits. The meadowlark and bald eagle appeared. Troutand salmon moved into the rivers.Montana’s weather patterns, geography, watersheds, vegetation, andanimal life settled into their currentpattern for a few thousand years.The “Ice Age” may sound like a very long time ago, but many scientists believe that another Ice Age will happen in the future as the cyclecontinues.FIGURE 1.8: Glaciers carved U-shapedvalleys between the mountains as theypushed rock and earth ahead of them.You can tell by looking that glaciersformed this valley above Lake Josephinein Glacier National Park. Rivers carveV-shaped valleys.FIGURE 1.9: If you live in Missoula, Great Falls, Glendive, Cut Bank, Hamilton,or Choteau, hold your breath. Where you live now was once the bottom ofhuge lakes formed by glaciers during the Ice Age.CutBankGLACIAL LAKECUT BANKChoteauCascadeMissoulaGLACIAL LAKEGREAT FALLSGLACIALLAKEJORDANMosbyGLACIAL LAKEMUSSELSHELLHamiltonvieRstonllowYeScale in Miles010 20 30 40 50016 32 48 64 80Scale in KilometerserhornRivGallatin RivergBi dison RiveMarJeff erso n R iv e Riv erWolfCreekCircleJordanPoSt. IgnatiusGLACIALLAKEMISSOULAGreatFallswGlacial LakesContinental Ice SheetsIce Caps, Alpine, and Piedmont GlaciersModern-day Cities and TownsIce Age Montana1 — MONTANA: WHERE THE L AND WRITES HISTORY9

Geologic Forces Still Shape the LandThe geologic forces that formed the land are still actively changing ittoday. Every little earthquake or geyser is a reminder that the construction of the world is still going on.Earthquakes: The Intermountain Seismic BeltFIGURE 1.10: Geysers on the Yellowstonecaldera spew steam and boiling water everyday. Still, pressure is building beneath thecaldera, and scientists say it will blow againone day. Will it be in your lifetime?You may not be able to feel it very often, but the earth’s crust is stillmoving and shifting. Up to ten small earthquakes occur in Montanaevery day, most of them detectable only by sensitive equipment. In fact,Montana ranks number eight in the nation in number of earthquakesper year.All along the backbone of the Rocky Mountains, from Kalispell in northwest Montana south through Utah, stretches a region of active earthquakefaults. It is called the Intermountain Seismic Belt. This is where earthquakesare most likely to happen as the crustal plates continue moving againsteach other. Two of the largest historic earthquakes in this region happenedwithin this belt, one in 1983 near Borah Peak, Idaho (measuring 7.3 on theRichter scale), and the other in 1959 at Hebgen Lake, Montana.Volcanoes: Is the Yellowstone Caldera Ready to Blow Again?Yellowstone National Park, on the southern edge of Montana, givesvisitors an insight into the power of the geologic activities that helpedform the Rocky Mountain region. About 2.1 million years ago, moltenrock exploded through the earth’s crust here. It was a cataclysmic(violent, sudden) eruption more powerful than the world had ever seen.This explosion spewed so much magma out of the earth that it createda gigantic caldera, or crater, 50 miles long, 37 miles wide, and severalhundred yards high.The eruption spewed plumes of smoke, ash, and gas into the stratosphere, circling the earth many times. It clouded the skies enough tochange the climate of North America. This ash layer is detectable in drillholes beneath the Gulf of Mexico. The volcano also sent great rivers ofash, pumice, and gas over the land, creating great lava beds throughoutthe West.The top of that volcano collapsed back into the center, built up,and erupted two more times. The last eruption was about 650,000years ago. It formed the present Yellowstone caldera (a largecrater formed by a volcanic explosion or the collapse of a volcanic cone).Today the Yellowstone caldera is 53 miles long and 28 miles wide andis the largest known single eruptive area in the world. Volcanologists(scientists who study volcanoes) calculate that in some places the groundhas risen 28.5 inches in the past century. Looking at the pattern of cataclysmic volcanic action at Yellowstone, they wonder if the world is due10PART 1: BAC K THROUGH TIME

for another spectacular eruptionsometime soon.Erosion Gives,Erosion Takes AwayErosion (the wearing away ofsoil and rock by ice, water, orwind) happens much more slowlythan volcanoes or earthquakes.Yet erosion has shaped parts ofMontana in many important andbeautiful ways. In eastern Montana,the Missouri and Yellowstone Rivers have eroded below the level of thegrassy plains (high-elevation grasslands) to create rugged buttes, bluffs,and badlands.Erosion can benefit agricultural lands by moving rich topsoilsdownriver and downhill into valley bottoms, creating good farmland.Erosion also hurts Montana’s agricultural land by washing nutritive(providing nutrition) soils farther downstream to other places.The Three EcologicalRegions of MontanaHave you ever driven all the way acrossMontana, from the mountains of the west,across the Continental Divide, over theRocky Mountains, through the foothills, andout onto the grasslands of the east? In someways our state is like three different countries. Within its boundaries lie three distinctlydifferent ecologies: the western (ColumbiaPlateau), central (Rocky Mountain Front),and eastern (Northern Plains) regions.Geography, climate, and resources haveshaped the history and culture of eachregion differently.The Western Region: RuggedMountains, Forested Ridges,High PrecipitationWestern Montana is crumpled into continuous mountains, winding rivers, andthick forests. If you live in this region,FIGURE 1.11: People ran into the street intheir nightclothes when a series of earthquakes hit Helena in October 1935. Theearthquake killed four people, damagedhouses and businesses, and destroyedHelena High School, shown in this picture.Aftershocks stretched out over two weeks.Exactly the Right Place“The Crow Country is good country. The Great Spiritput it exactly in thhase right place; while you are in it yofare well; whenevuer you go out ofit, whichever waytravel, you fare wyouorse . . . The CrowCountry is exactlyin the right place. It has snowy mountains and sunnyplains, all kinds ofclimate and goodthings for ever yseason. When thesummer heats scorch the prairies,you can draw upunder the mountains where the airsweet and cool, thise grass fresh, andthe bright streamcome tumbling oust of the snowbanks. There you canhunt the elk, thedeer and the antelope when theirare fit for dressinskinsg; there you willfind plenty of whbears and mountiteain sheep. In theautumn when youhorses are fat andrstrong from the mountain pasturesyou can go downinto the plains andhunt buffalo, ortrap beaver on the streams. And when winter comesyou can take shelon,ter in the woodybottoms along thrivers . . . The Croew Country is exactly in the right plaEverything goodce.is to be found there. There is no cotr y like the CrowunCountry.” —ARAPOOISH,CROW LEADER, 18331 — MONTANA: WHERE THE L AND WRITES HISTORY11

you probably see mountains wherever you look. The only way throughthe mountains is by natural passes—low saddles between the peaks.Between the mountains lie wide, fertile valleys with rich soil thathas been nourished by geologic activity and precipitation (rain andsnow) over thousands of years. Moisture-laden clouds moving in fromthe Pacific Ocean hit the tall mountains and drop an average of 15 to23 inches of precipitation per year. In some areas it snows more than300 inches per year. As a result this region is greener and supports morevegetation than any other region of the state.FIGURE 1.12: Lush, mountainous westernMontana is tree-covered and dotted withlakes. This painting, called The Flathead,by Montana artist R. E. DeCamp, hangs inthe Montana state capitol building.12PART 1: BAC K THROUGH TIMEWhat to look for: Montana’s western rivers feed the Columbia River, which flows westto the Pacific Ocean. Flathead Lake, encompassing 197 square miles of northwesternMontana, is the largest natural freshwater body of water west of theGreat Lakes. Ash, elm, cedar, and larch trees grow only in the western region. The tallest pine tree in Montana is a 300-year-old ponderosa pineover 180 feet tall, growing near St. Regis. A grove of giant cedar trees, unlike any other trees in the state, growsnear Libby. Most of Montana’s grizzly bears live in western Montana. Beargrass and bitterroot (the state flower) grow mostly in the westernregion.

FIGURE 1.13: BeargrassFIGURE 1.14: Giant cedarsFIGURE 1.15: Grizzly bearCentral Region: Isolated Mountains, High Plains, Chinook WindsCentral Montana spreads east from the foothills of the Rocky Mountains.Its small, scattered mountain ranges rise above gently rolling plains.The most prominent mountain clusters in the central region are theSweetgrass Hills, the Bear’s Paws, the Little Rockies, the Highwoods, theMoccasin-Judiths, the Big Snowys, the Crazys, the Pryors, the Big andLittle Belts, and the Bighorns.Here the Rocky Mountains create a rain shadow (an area on theinland side of a mountain range that is dryer because it is sheltered fromrain-bearing clouds). Precipitation in central Montana averages only 12inches per year. Trees and other vegetation are more sparse than in themoist western region. Temperatures in the central region can range from–40ºF to 105ºF.The central region is Montana’s “Chinook Corridor.” Chinooksare blustery, warm, dry winds that blow down the eastern slopes ofthe mountains and can raisetemperatures as much as 50 degrees in several hours. They canmelt a snowbank in an afternoonand rob the soil of moisture. SomeIndians called the chinook windthe “snow eater.”Another wintertime phenomenon of the high plains east ofthe Rockies is the Alberta clipper,a frigid, dry wind that forms onthe high plains of Alberta, Canada,and cruises southeastward like aship sailing over the land at 40 to60 miles per hour. Alberta clippers rarely leave more than a fewinches of powdery snow, but theybring ground blizzards, subzerotemperatures, and serious drifting.FIGURE 1.16: High, fertile valleys rimmedby mountain ranges characterize centralMontana, as in this photo of the CrazyMountains, near Lennep.1 — MONTANA: WHERE THE L AND WRITES HISTORY13

FIGURE 1.17: Mule deerFIGURE 1.20: The plants of easternMontana are well suited to drought.Yucca, for example, have a thick skin oran oily coating to reduce evaporation(loss of moisture to the air). In an imagehe called Prairie Awakening, Montanaartist Clyde Aspevig painted these yuccain bloom.FIGURE 1.18: Bald eagleFIGURE 1.19: Silvery lupineWhat to look for: Ponderosa pine, Douglas fir, and spruce trees cover the mountains, while bluebunch wheatgrass, timothy grass, and fescue fill thegrasslands. Lupines, larkspur, and Indian blanketflower grow on the hillsides,and prickly pear cactus and sagebrush grow in the lowlands. Montana’s two largest river systems, the Missouri River and theYellowstone River, begin in central Montana. Mule deer and pronghorn spread throughout the lowlands, withblack bear, elk, and moose in the forests and hills. Pheasants, sage grouse, and Hungarian partridge hide in the brush,and hawks, falcons, and eagles soar in the sky. Trout, sturgeon, and bass are the most important fish species.Eastern Region: Rolling Plains,Persistent Winds, the Endless SkyEastern Montana is almost uninterrupted grassland. Here the MissouriBreaks and the badlands in MakoshikaState Park form two of the most dramatic examples of a landscape sculptedby water and wind erosion.Eastern Montana is dry, windy, andextreme. Temperatures here are oftencolder in winter and hotter in summerthan in the rest of the state. Arctic stormsblow in blizzards and extreme cold fromthe north. Summer hailstorms sometimesruin crops. Yet, with all this storm action, eastern Montana receives only anaverage of 11 to 14 inches of rain peryear and sees many years of drought,making water extremely important in thisarea. Ranches and farms require more14PART 1: BAC K THROUGH TIME

FIGURE 1.21: Wild turkeyFIGURE 1.22: Prickly pear cactusFIGURE 1.23: Pronghornirrigation (bringing in a supply of water to make farmland more productive), more space for grazing, and a little more patience than in the otherregions. The towns are small and far apart.What to look for: The Fort Peck Dam forms the Fort Peck Reservoir on the MissouriRiver—the fifth-largest human-made reservoir in the United States(134 miles long, 220 feet at its deepest, and 1,520 miles of shoreline). Woody shrubs like juniper thrive in the dry, elevated soils of easternMontana, while ponderosa pine, Douglas fir, and spruce trees growin the high elevations. Plants include sage, yucca, shrubby cinquefoil, prickly pear cactus,snakeweed, and rabbitbrush. Native grasses like needle-and-thread grass, bluestem wheatgrass,and grama grass were perfectly adapted to the bison, whose hoovesagitated the topsoil just enough to spread grass seeds easily withoutdisturbing the roots. Even warm-water prairie streamsthat seem lifeless actually teem withhundreds of fish species. The legendary paddlefish can grow to 100pounds. Pronghorn, jackrabbits, weasels, andporcupines live in the hills and plains.You are likely to see wild turkeys hereas well as Hungarian partridge, sagegrouse, and pheasant.FIGURE 1.24: Sculpted sandstone,brush-filled gullies, and great hikingcountry spread out before you ineastern Montana. This photo wastaken near Jordan.A Land of ContrastMontana is a land of many opposites.Temperatures can get as cold as –70ºF inthe winter (Rogers Pass, 1954) and as hotas 117ºF in the summer (Glendive, 1893,and Medicine Lake, 1937). Its lowest point1 — MONTANA: WHERE THE L AND WRITES HISTORY15

is only 1,892 feet above sea level (Kootenai River Valley), while its highestpeak is 12,693 feet high (Granite Peak, near Yellowstone National Park).The state has many rivers and lakes—yet drought is a constant threat.The land is rich in gems, minerals, gas, oil, wildlife, grazing land, andtopsoil—yet it struggles economically. Many people enjoy Montana’sopen land and distance from large cities, but these features make transportation one of our highest expenses.Mountains: The Backbone of MontanaMontana’s name came from the Spanish term Montaña Relucientes, whichmeans “shining mountains,” a Spanish translation of what the Indianscalled the Rocky Mountains. There are 28 important mountain rangesin Montana, and about one-third of the land is mountainous. TheContinental Divide of the Rocky Mountains divides the westward-flowing rivers, which run into the Pacific, from the eastward-flowing rivers,which eventually run into the Gulf of Mexico.Mountains, hills, buttes, bluffs, and cliffs have played an importantpart in Montana history. They influence climate, vegetation, and wildlife. They determine transportation routes. They contain valuable gemsand metals. Sometimes they can be used as tools, as when early Indianpeople hunted bison at a buffalo jump.FIGURE 1.25YMBEAR’S PAWMTNSTeton RiverFR ON LFMTNSEMontana’s Rivers and MountainserRiverPowdPRYORMTNSLittleMRiv issoer uriBEARTOOTHMTNSor nerR iv er RivTona teLittle BighS till wERANGROKARANGErgue RiverYeltonlowsGPART 1: BAC K THROUGH TIMEshell RR AN120BINGECENTENNIAL MOUNTAINSSATINdRJeBig Hole RivrheaONBeaveM A DI SINMusselCASTLEMTNSGALLiverMTNBitterroot RBELTerBLACKTAILMTNS SNOWCRESTRANGERTENDOY ed Rock RiverMTNSit hverRi v90ur iOSTARUBYRANGEY RAVELLGRAM1660INNTA30UNriveJu dSEEPBIG SNOWYMTNSBRIDGERRANGEn RiverHIGHLAND fersoerMTNS fPIONEERTOBACCO ROOTMTNSMTNSM OUEA DERHOTBEAVRROBITTE0BIGNSUNTAINSIRE MTiverSAPPHMOMilesssoO MiORMTNABSARDAEANGon RiveMadisrGallatin RiverERCONiSmith RTTANAELKHORNMTNSELTHGSt ondBIFLINT CREEKRANGELE BJUDITHMTNSor ntheak FlaS. ForEMI S S I O N M TN SANGHIGHWOODMTNSLITTETC l a r RANGEkForkRFort PeckLakeMissouri R erivSun RiverGARNLITTLEROCKY MTNSghNTAINOUNRGEB l a ck f o o t R i v e rTrMissouri RiveCKDSWARANerwsROHE Aiver FlatheadRiverMilkRivias RiverYelloEFLATNSERTN SMarFlatheadRiverMToTNST M lark FCAD’EMANGISHINECO UFlatheadLakeSWEETGRASS HILLSBIS RISCABrkRMerRivi lkClaYell rks iverLE NorkN. F dhea EFlat H RANGWHLakeKoocanusaPURCELLMTNS

Travel across many of these mountains would have been impossibleif geologic forces had not carved passes across which people could moveto hunt, trade, communicate, and ship goods.Rivers: Three Major River Systems Feed the LandOne of the things that makes Montana unique (one of a kind) is itsrivers. Within Montana’s boundaries lie the headwaters (the source ofa river) of three major river systems that run into three different seas.The Columbia River system flows into the Pacific Ocean; the

them happened very slowly. Some happened suddenly. Most geologic changes happened very slowly, too—over millions of years. Some hap-pened in sudden, catastrophic events, such as a fl ood, an earthquake, or a volcano. To really see how much you have changed, you would want to look at a picture taken on the day you were born. Scientists .