Part 2 Teton Country

The Mountains

The tight concentration of tall peaks and pinnacles called the Cathedral Group has been described as “Chartres multiplied by six, a choir of shimmering granite spires soaring high above the nave and transept of the valley below.” Few fail to be impressed by these most scenic of mountains and by their staggering panoramic quality. Theodore Roosevelt, so often given to eloquence, called this “the most beautiful country in the world.” You may find yourself spending an inordinate amount of time just staring at the mountains.

The Tetons, being classic fault-block mountains, were originally mound-like, not jagged and spired. They were formed as the Earth cracked along a north-south line at the base of the mountains. As the Earth’s outer crust faulted under pressures deep within its mantle, the western block tilted upward and the eastern block sank. We speak about this mountain building in the past tense because, for us mortals, mountains symbolize eternity. But the action continues.

The Tetons are the youngest mountains in the Rocky Mountain system, but they are made out of some of the oldest rock in North America. The granitic gneisses and schists north and south of the central, highest peaks are some of the hardest and least porous rocks known. The rock of the Grand Teton is a younger granite. These qualities, and the accessibility of major peaks, attract technical rock climbers. The handholds are secure and the views breathtaking.

The geologic time scale is so vast we cannot imagine it. Most of us simply refuse to imagine more than a few thousand years: we find anything greater too inhibiting. The Ice Age ended its major glacial action about 10,000 years ago, the beginning of the Holocene or the Recent, as early man wandered the glacial ice margins. But seven-eighths of Earth history are tied up in the Precambrian Period, the period of formation of the Teton Range’s 3.5-billion-year-old rocks. By contrast, just east of Jackson Hole—Thermopolis on your Wyoming highway map—there is now forming the youngest rock in the United States, travertine. Further proof that geologic processes continue.

The massive Teton Range contains a miniaturized world on a different time scale. The alpine world is a summer surprise because it offers flowering displays long after the valley show concludes for the season. Bloom time is delayed by ascending altitude: the rule of thumb is about 12 days delay per 1,000 feet. If you miss the yellow buttercups at lower elevations, climb higher and you may overtake their montane flowering in full bloom. Such are the rigors of alpine tundra life that here the flowers largely depend on wind for pollination, or on flies, rather than on bees. Bees cannot withstand the cold temperatures so common at these heights. The alpine insect explosion is brief, but ants, ladybugs and other beetles, and diminutive grasshoppers inhabit the alpine world. They make fast food for alpine-nesting birds, such as pipits, horned larks, white-crowned sparrows, and rosy finches that are desperately trying to nourish their hungry broods between the two edges of winter.

Specialized and severe, the alpine world is sparsely populated. Here eagles and weasels hunt for bird nestlings, marmots, pikas, pocket gophers, deer mice, and voles. The heartbeat of the extremely fragile tundra is slow by necessity. That any plants have adapted to this environment seems incredible. Yet alpine laurel fills rock crevices. Spring beauty blooms in pockets of soil. Mats of moss campion carpet slopes of shattered rock. White columbine nod in the wind shadows of larger rocks. Alpine sunflowers blaze like a galaxy of equal suns, their disproportionately large flowers awkwardly seated on abbreviated stalks.

The process of developing from bare rock to fully developed alpine vegetation might require thousands of years. By contrast, it is estimated that 100 years are required to form one inch of soil on the plains. On alpine heights the rate is many times slower. The first plants to colonize bare mountain rock might be lichens, multi-colored crustose plants adapted to extreme conditions. Lichens are tough. They grow on rocky outcrops near the South and North Poles. They also thrive on desert rocks that are too hot to touch. Lichen plants can first be dried in air and then in a dessicator and then exposed to 514°F for up to seven hours and yet, upon return to room temperatures, they will resume normal metabolism. And lichens regulate, to some extent, water flow at high elevations. On dry days their water content may be from two to ten percent of dry weight. On rainy days that may soar to more than 300 percent. Mats of lichen hold so much moisture that even a rise in barometric pressure may press some water out to resume its tortuous trip toward the Pacific Ocean.

Seven Teton peaks exceed 12,000 feet and one, the Grand Teton, pushes above 13,000 feet to 13,770 feet in elevation. At such heights, conditions support mountain glaciers. The Teton Glacier is one of about a dozen small alpine glaciers cradled in shaded east- or north-facing cirques among the high peaks. Teton Glacier occupies a spectacular cirque that faces east between the north face of the Grand and Mount Owen. It is partially fed by avalanches from the cliffs around it. Some of these cliffs are more than 3,000 feet high. The glacier’s terminus has retreated markedly since 1929, but the rate of loss was less between 1954 and 1963 than it was between 1929 and 1954. The mountain glaciers in today’s Tetons are not left over from the Ice Age. They began forming about 500 to 1,000 years ago, during the so-called Little Ice Age.

As insignificant as these glaciers are compared to the colossal sheets that repeatedly lumbered through the Tetons and Jackson Hole, they slowly exact a toll on this hard rock, continuing to carve, etch, and abrade the range. They host life too: algae of a reddish hue that give rise to the phenomenon called watermelon snow.

The Teton Range

Any mountain range is the product of the struggle between uplift and erosion, but in few places are the results as clear as on the crest of the Teton Range. Today we do not first see the Teton peaks across 160 kilometers (100 miles) of wilderness and then struggle to them afoot, on horseback, or by wagon. This spectacle may break upon us from the window of an airplane, or appear around a bend in the John D. Rockefeller, Jr. Memorial Parkway. The telescoping of time does not lessen the impact however. The range’s nearly even east base (see painting) is the best place from which to grasp its formation. Along this line the valley ends at an abrupt wall, with no foothills at the mountain’s base. These are sure signs of faulting, the elevation of a mountain block along a deep crack in the Earth’s crust. (See diagram.) Shatter lines visible in many of the naked rock peaks show that the uplift was no smooth ride. The Tetons are very young mountains composed of very old rock. The range was thrust up about 9 million years ago. Young? Yes, when compared to the main Rocky Mountains, which rose 60 million years ago, and the Great Smoky Mountains, which have been above water more than 200 million years. The Teton Range’s crystalline rock is comparable to the 3-billion-year-old Allegheny Mountains core. This hard, stable rock, more than 300 times older than the mountains it forms, is a boon to climbers.

Another unusual feature of the Teton Range is its divide, the division line at which water will flow off the mountains either west into the Teton River or east into the Snake. The Teton’s divide lies well below and to the west of the highest elevation. This is because the steeper east face caused water to flow off faster and thereby to cut deeper. These streams carved into the range and captured headwaters from less erosive western streams. Erosion and uplift continue competing in the range, which still rises through periodic earthquake activity.

1. Mount Wister 2. Shadow Peak 3. South Teton 4. Cloudveil Dome 5. Nez Perce Peak 6. Middle Teton 7. Mount Owen 8. Teewinot Mountain 9. Rockchuck Peak 10. Mount St. John 11. The Jaw 12. Mount Woodring 13. Maidenform Peak 14. Mount Moran 15. Window Peak 16. Bivouac Peak

Forming and Shaping the Mountains

Upthrown fault block Gentle western slope Teton Fault Steep eastern face (_Horn-shaped peaks and U-shaped valleys_) Valley floor filled with sediments Down-dropped fault block

Teton Country Lakes

With only a brief itinerary in the park you might leave Jackson Hole with a memory of the high peaks and just one lake, much the impression that postcards give. But there are dozens of lakes. Most must be sought off the highway behind fringes of trees or up a short reach of trail. Some nestle in the alpine heights. A checklist of park lakes based on how they were formed includes surprising variety. A few are oxbow lakes, cut off meanders of the Snake River. Two are real oldtimers, Emma Matilda and Two Ocean Lakes, formed about 30,000 years ago as the glaciers melted back. But most are new glistening souvenirs of the latest glacial advance that ended 8,000 years ago. This newest crop is readily identified by the morainal dams that back up each lake. Most easily recognized is the morainal dam of Jenny Lake. Unlike Jackson (large photo), Jenny, Bradley, Taggart, Leigh, and Phelps Lakes mark surfaces gouged by mountain glaciers. The many small ponds dotting the sagebrush flats, such as The Potholes, are not gouge scars, but pits. Here glacial outwash materials surrounded and buried small ice masses that later melted. The technical term for these depression ponds is kettle ponds, but The Potholes were named by a rancher, not a geologist. The Tetons’ highest lakes are called tarns (small photo). Bearing names such as Surprise, Grizzly Bear, Bear-paw, and Rimrock, these are diminutive versions of the glacial lakes at the foot of major canyons. They originate in ice-scoured pockets and are still forming under the small glaciers at the heads of highcountry canyons. The largest and most heavily fished lake is Jackson Lake. Cutthroat trout are native, but lake trout (Mackinaw) were introduced in the 19th century. The lake is 130 meters (425 feet) deep and 26 kilometers (16 miles) long. Jackson, a natural lake, was dammed before the park was established to store more water and control the Snake River for irrigation in Idaho. The Teton country’s lake and pond environment has benefited moose and ducks the most, but nearly all park denizens—vacationing _Homo sapiens_ included—appreciate this aquatic resource. One species, the beaver, extends its appreciation by creating more ponds. Once nearly exterminated during the trapper’s era, beaver are now abundant here.

Mountain Climbing

The Mountain World

Above the tree limit and around snowfields and glaciers lies the alpine tundra. This fragile ecosystem challenges plant and animal survival with temperature extremes, high winds, a short growing season, frequent drought, and poor soil. Basic plant survival adaptations include dwarfism, oversize root systems, matting growth, succulent leaves or stems, and warmth-producing red pigments. Some high mountain plants are almost brown, not green, but perfectly alive. Dwarfism and matting keep plants snugged low to the ground where conditions are less severe than just a few centimeters higher. Animals tend to adapt to subalpine and alpine rigors by modifying their behavior rather than their structure. Exceptions include flightless grasshoppers and the pika’s fur-covered feet.

The summer alpine tundra provides insects, seeds, leaf crops, lichens, and fungi as wildlife food. For this short season animals are well supplied and may become conspicuous. Birds, with their advantage of flight, can cover vast areas quickly in the search for food. They can also readily change ecozones. A bird flying from alpine tundra down to a forested slope makes a journey between ecozones equivalent to migrating from above the Arctic Circle to northern Maine. Hawks and eagles, in a regular search for pikas or mice, can cover all of the Teton high peaks in 2 hours or less.

1 _Prairie falcon_ 2 _Pika_ 3 _Yellow-bellied marmot_ 4 _Cushion buckwheat_ 5 _Whitebark pine_ 6 _Subalpine fir krummholz_ 7 _Dwarf willow_ 8 _Pixie-cup lichen_ 9 _Black rosy finch_ 10 _Alpine forget-me-not_ 11 _Moss campion_ 12 _Haircap moss_

The Valley

With the Louisiana Purchase treaty signed, President Thomas Jefferson wanted to know what he had bought, so he sent the Lewis and Clark Expedition overland to the Pacific in 1803 to find out. On the return trip John Colter left the expedition along the Yellowstone River to stay in the West and join a trapping venture. He is considered the first white person to discover what is now Jackson Hole. Colter supposedly wandered through this high, mountain-encircled valley—trappers called such valleys holes—in the winter of 1807-1808. Colter was soon followed by other trappers, and 40 years later the trappers were followed by homesteaders. Several homesteaders became dude ranchers, and their dudes were followed by vacationers, who now number nearly three million each year.

The flatness of Jackson Hole comes as a surprise, considering that the Teton Range was formed by a fault-block process. You would expect a deep valley, but it has been filled repeatedly by rock debris transported by glaciers and their meltwaters. The Snake River does little cutting into the valley floor today. The flat areas above the river, called benches, were carved out when the river had the torrential force of glacial meltwater. The river’s north-south flow shows that the valley slopes southward. The valley also tilts westward, toward the fault that gave rise to the Teton Range. For reasons not fully known, the valley has sunk more than the mountains have risen. We know this because a sedimentary cap of rock atop Mount Moran—nearly 6,000 feet above the valley floor—was once connected to the same rock layer that now lies an estimated 24,000 feet below the valley surface.

The glacial material that fills the valley is largely quartzite rock rounded by tumbling in running water into softball- to basketball-sized cobbles, supplemented by gravel, sand, and silt. This rock came from long-vanished mountains to the northwest. The depth of the valleys cobble material is estimated at perhaps about 2,000 feet. This cobble material has been washed by glacial runoff so often that it lacks the clay content that is essential for the ground to retain water. Melting snow and rain rapidly percolate through, so that only grasses and other plants adapted to arid conditions can thrive in the valley’s coarse-textured soil. This is why sagebrush dominates the valley floor, except where streams and ponds provide enough water for willow bushes, spruce, and cottonwood trees. Lodgepole pines grow atop the recent glacial moraines that contain sufficient nutrients and clay, such as the one surrounding Jenny Lake.

Geologic forces have not always been subtle influences in the valley. Melting snow and heavy rains in June 1925 saturated a layer of clay sandwiched between sedimentary rock layers that form the north end of Sheep Mountain, near Kelly. An earthquake, probably, triggered an enormous landslide, and thousands of tons of debris raced down into the river, damming it and backing up a lake 5 miles long and 200 feet deep. Two years later the top 50 feet of the dam broke off and a wall of water rushed down through Kelly, leveling all buildings except the church and school. Six lives were lost, despite ample warning. The landslide scar on Sheep Mountain’s north end is more than 5,000 feet long and 2,500 feet wide. Geologists say that more of Sheep Mountain is perched to slide, given similar spring rainfall and an earthquake trigger.

The rise of the Teton Range and the corresponding sinking of Jackson Hole continues, although not at an even rate. The action continues by irregular crustal movements known as earthquakes. Geologist John D. Love, longtime interpreter of the dynamics of the Teton Range, feels that a major earthquake movement along the Teton fault, of as much as 20 feet, could happen at any time. The impact would be many more times severe than the landslide and ensuing flood at Kelly. But such things are not given to easy and precise prediction.

The Elk Herd

The Jackson Hole elk herd is free ranging and migratory. About half of its 15,000 elk winter on the National Elk Refuge. By midsummer, many graze on bunchgrass in high meadows near the Continental Divide, more than 110 kilometers (70 miles) to the north. Moving north in spring, the elk feed on succulent new growth of grasses and forbs in the sagebrush flats. Cow elk, pregnant since last fall, separate from the main herds to linger on calving grounds. Newborn elk hide in sagebrush or aspen cover while the cows feed. Elk tend to feed in the open in morning and evening, retreating to forest shade during the day. All summer they gain weight in preparation for winter. Full grown cows often exceed 230 kilograms (500 pounds). Bulls may stand 1.5 meters (5 feet) at the shoulder and weigh 405 kilograms (900 pounds). After their antlers drop off in March, bulls begin growing a new annual set. Antlers, furry nubbins in May, become velvet covered branches by July. By late August the velvet, which supplied blood and nutrients for rapid antler growth, hangs in tattered shreds as bull elk rub their antlers against flexible saplings. In September, mature bulls polish the velvet from their antlers and join the cows on their summer ranges. Then the dominant bull elk gather harems of 6 to 20 cows. These bulls establish and maintain dominance by displaying massive branched antlers, impressive bugling, chasing off less aggressive bulls, and occasional combat with other males. Fall migratory herds sometimes number 200 or more. Migration begins when the snow reaches a critical depth. It is a special experience to witness this exodus of elk streaming down the valley. Many elk return to winter on the National Elk Refuge and in the Gros Ventre drainage. Supplemental feeding is provided on the refuge to maintain the Jackson Hole herd because some two-thirds of its traditional winter range has been lost to development. The remaining habitat, and the elk hunt permitted by the law that added Jackson Hole to the national park, is cooperatively managed by the National Park Service and other Federal and State agencies to perpetuate and protect the majestic elk of this great herd.

Settling the Valley

Shoshone, Crow, Blackfeet, Gros Ventre, and other Native Americans hunted and picked berries in the valley in summer, but winter was unbearable. During the early 1800s, solitary mountain men trapped valley beaver, sometimes wintering through intense and deep snow. After the fur trade collapsed in 1840, occasional trappers and prospectors ventured into Jackson Hole. Well-known pioneers built temporary cabins. Jackson Hole was settled late in the frontier era, when limited technology, supply routes, and food storage made winter bearable. The first permanent settlers, John Holland and John Carnes, homesteaded north of the town of Jackson in 1884. Significant settlement came after 1900 as schools, post offices, and churches were built. Jackson, Wilson, Moran, and Kelly became the dominant communities. Getting supplies and mail into Jackson Hole was always difficult. Most supplies came from Idaho over rugged Teton Pass. Pack horses and supply wagons then faced the Snake River, often dangerous or impossible to cross. Menor’s Ferry, built at Moose in 1894 by William D. Menor, was a major crossing until replaced by a bridge in 1927. Ferries, and later bridges, at Wilson also improved valley transportation. Most valley homesteaders became cattle ranchers, grazing their herds on the public range and cultivating enough hay for winter feed. But the harsh climate and porous soils made ranching risky. When some ranchers recognized the value of scenery and wildlife, they began operating dude ranches and hunting lodges. In 1903, Ben Sheffield catered to wealthy hunters from his headquarters at Moran. In 1907, Louis Joy operated the first dude ranch in Jackson Hole, the JY. The age of tourism had begun.

The Snake River

Grand Teton National Park and Jackson Hole have no corner on the Snake River, boasting as they do a mere 40 miles or so of the sinuous Snake’s more than 1,000 miles of progress from the Continental Divide near Yellowstone National Park to its confluence with the mighty Columbia River near Pasco, Washington.

Judging from its almost leisurely mid-summer passage as a braided river through the park you would not guess what chaos lies downstream. The river had at least two names before the Snake was affixed. A group of French-speaking trappers who crossed the river in September 1811 encountered such difficulty they decided to give it the name Mad River. Sometime later this trapping party had to cross it again downstream near its confluence with the Hoback River and renamed it _La Maudite Rivière Enragée_—Accursed Mad River. Those names properly hint at what lies downstream as the Snake flows in every direction but east in a great sickle-shaped curve, its watershed embracing the largest chunk of wilderness in the United States outside Alaska. The Snake’s beautiful Shoshone Falls in Idaho is a full 43 feet higher than Niagara Falls. And the Snake’s Hells Canyon, also in Idaho, is North America’s deepest and narrowest major gorge, averaging a deeper gash across the land than the Grand Canyon itself. Hells Canyon plunges 7,900 feet at its deepest point. What is more, it averages 5,500 feet deep over its course.

In a valley this high (the elevation of Jackson Hole at the lower end measures 6,000 feet) the Snake should have cut, with its steep gradients, permanent channels. Instead, it still wanders in myriad channels across the glacial debris filling the fault basin. Here the Snake looks more like a prairie river rambling with the restlessness of youth. Its banks are a checkerboard of successional stages, as plant communities rise and fall with disturbances created by flooding, channel shifting, or fire. This benefits the moose and beaver by assuring continual supplies of willow and cottonwood that would otherwise soon be succeeded by blue spruce.

The Snake, discovered by Lewis and Clark in 1805 but not fully explored until its headwaters were pinpointed in 1970, is no longer a completely wild river even in the park. Jackson Lake Dam, built before the park was established, controls the water flow below the lake, moderating natural surges that used to follow rapid spring snowmelt or violent summer thunderstorms. Since the river no longer scours the valley regularly, these stabilized conditions favor the development of larger tracts of blue spruce.

Compared to the lakes, the Snake harbors a wealth of aquatic life. A river is richer partly because its linear structure provides more shoreline. The plant complex that the river makes possible continually enriches the water with leaves and other debris. This energy subsidy, along with the countless terrestrial insects caught by the river, is passed up the food chain. Eventually the additional energy is translated into the fish that help support the herons, mergansers, eagles, ospreys, otters, and other terrestrial predators that use the aquatic food pyramid.

The plant and animal composition of the riverine world varies with the rate of water flow. In slow water areas, such as the Oxbow Bend, where the river has cut off and abandoned a former looping meander, bottom-rooted aquatic plants attract herbivorous animals—moose, mallards, golden-eyes, and cinnamon teals—to graze these underwater gardens. Such quiet stretches also attract carnivores to exploit the greater variety of prey. Great blue herons stand motionless along the shoreline, waiting to spear passing fish or the mice, frogs, and snakes at water’s edge. Mink and coyote patrol the shoreline.

Insects are important river denizens, as the fly fishing angler’s art attests. The nymphs of mayflies and stoneflies and the larvae of caddisflies eat algae and other plant detritus, in the process becoming attractive fare for the cutthroat trout and Rocky Mountain Whitefish. The caddisfly larvae have adapted to fast water by constructing protective body cases from sand grains, pebbles, plant stems, and other stream bed materials. The faster the current, the heavier the case, which enables the larvae to settle rapidly into a new cranny, should they be swept away.

The sturgeon used to populate the Snake in what are now park waters, but the erection of more than 20 hydroelectric and irrigation dams downstream so changed the river that these very large fish are now hard pressed to survive above the Columbia River confluence.

Expeditions and Trappers

Jackson Hole witnessed the exploration, settlement, and exploitation that characterized the opening of the West. Early events centered around the fur trade and survey expeditions. John Colter generally gets credit as the first white man to visit the valley, purportedly crossing it in the 1807-1808 winter. Colter trekked west with Lewis and Clark and got permission to leave them on their return east. Other trappers whose names pop up before Jackson Hole’s fur trade died out in the 1840s are Jedediah Smith, David Jackson, William Sublette, Kit Carson, and Jim Bridger. All were inveterate explorers and adventurers. Sublette probably named the valley, after his trading partner, Jackson. The fur trade died out when beaver hats—the prime pelt market—went out of fashion in Europe. By then, beaver had been severely reduced over much of North America, anyway, and a process for making felt from far cheaper rabbit pelts had been developed. The first survey expedition ventured into Jackson Hole in 1860, guided by Jim Bridger. In command was Capt. William F. Raynolds, topographical engineer. The War Department conducted these early surveys to find out about the Indians, farming and mining possibilities, and potential transcontinental routes. Raynolds turned thumbs down on a rail route here. In 1861 and 1862 gold seekers prospected the valley but found nothing. An Interior Department mission, the 1872 Hayden Survey led by Professor Ferdinand V. Hayden, explored the Tetons and Jackson Hole, guided by Beaver Dick Leigh. Many Jackson Hole features are named for Hayden Survey members. These include Jenny, Bradley, Taggart, and Leigh Lakes. An expedition led by Lt. Gustavus Doane nearly perished here in the 1876-77 winter and would have starved but for the fishing skills of one private. The color illustrations are by Jackson Hole artist John Clymer.

The Indians

No Indians made permanent, year-round homes in Jackson Hole. Winters were too severe. Before white settlement, a small, recluse Shoshone group camped in the area for as many months as possible because of repeated raids from northerly tribes who had British-supplied guns. Other Shoshone knew this small band as Sheep Eaters, because they depended on the bighorn sheep for food. They lived scattered in family groups, not as a tribe. When it seemed safe, they would fish, hunt, and gather plants, seeds, and berries. They used dogs as beasts of burden.

They made bows of elk antlers and sheep horns reinforced with elk and deer sinews. Early trappers seldom encountered the Sheep Eaters although they sometimes saw smoke from their fires. The Sheep Eaters stayed near the mountains until joining other Shoshone under Chief Washakie on reservations in Idaho and Wyoming about 1879. Some artifacts and other evidence of their life are still found today in the Tetons. Archeological studies show that various Indian groups migrated through here on a seasonal basis. The Shoshone peoples arose in the semidesert Basin of the upper Southwest. As food became scarce they migrated east of the Rockies, into the plains and mountain parks of Wyoming and Montana, probably in the 1500s or mid-1600s. In part they were escaping slave-trading Ute Indians. By 1730, however, records begin to show the Shoshone as the most important plains tribe. They were walkers until about 1740, when they got Spanish horses from the Comanches to the south. Mounted, they would raid as far as the Saskatchewan River to the north and the Black Hills to the east. During the whites’ overland migrations, the Eastern Shoshone, under Chief Washakie, avoided confrontations. But Chief Washakie knew his people’s nomadic way of life was over.

Cutthroat Trout

The 17 species of fish in Grand Teton National Park include brown, brook, rainbow, and lake (Mackinaw) trout. These introduced species are found in a number of lakes and streams. Perhaps the most impressive fish is the Snake River cutthroat trout, the native trout so dependent on the park’s natural aquatic system. The deep red or orange-red marks under its jaws give the impression of a slashed throat, hence cutthroat. The Snake River cutthroat is a distinct subspecies of the cutthroat trout identified by the hundreds of tiny dark spots on both sides of its body. In spring, particularly May and June, the Snake River cutthroat will travel upstream into tributary waters to spawn. The female digs a nest (called a redd) in the gravel and the male and female lie side by side while simultaneously contributing the sperm and eggs. The fertilized eggs settle to the bottom and hatch into fry within 40 days. The young fish usually remain in the tributary stream until fall but will sometimes wait a full year before migrating to the river. Juveniles, called fingerlings, and sub-adults feed on a variety of aquatic invertebrate larvae such as caddisflies, mayflies, and stoneflies. The older fish become more predaceous and feed on a variety of smaller species of fish living in the river. The cutthroat trout reach sexual maturity at three to four years of age. Few cutthroats live longer than five years. The post-spawning mortality rate is 50 percent. The Snake River cutthroat trout indeed delights the angler, but more important is its role in the wildlife community. The cutthroat consumes aquatic insects, invertebrates, and small fish, helping to keep these populations in check naturally. This trout is also consumed, providing food for bears, eagles, ospreys, and otters. If the fish population declines, so will the animals that depend on it for food. As fishing pressure continues to grow, park managers may have to protect this natural population of Snake River cutthroat to maintain the national park’s wildlife community.

Wildlife and Wildflowers

When the Shoshone Indians sat down with government officials at Fort Bridger in 1863 to conclude a treaty that would define their lands, the parcel that the parties arrived at totaled 30,000 square miles. A very small part of that was Jackson Hole, but this was such rich hunting ground in summer and fall that even the Shoshone dared not lay sole claim to it. Blackfeet, Bannock, Crow, Gros Ventre, and probably other tribes were drawn here to hunt. What would you have seen on a hunting trip in those days? Bison, pronghorns, and at least three times as many elk as exist here now, but far fewer deer. Near wall-to-wall beaver along the waterways, but nary a moose. And bighorn sheep peering down at you from nearly every crag and butte.

When settlement in the late 1800s at the south end of the valley eliminated about two-thirds of their winter range, as many as 500 elk sometimes ended up on the streets of Jackson on frigid nights. Winter starvation and poaching pressures took many elk.

The fur trade decimated beaver populations. But what of moose, deer, and bighorn? Moose and mule deer probably benefited from white settlement. Moose increased because of the suppression of fire, which permitted the increase of sub-alpine fir, a winter food source. Moose graze but little grass, mostly browsing coarser plants. Likewise mule deer. Livestock overgrazing hindered elk but favored moose and mule deer. The latter evidently usurped bighorn wintering range, reducing the sheep population. Wolves were extirpated and grizzly bears nearly so. That favored—within range support limits—every four-footed vegetarian not beset with other insurmountable problems.

Grizzly bears roam only the northern part of the park. Predation on large mammals must be carried out by seldom seen black bears, rare mountain lions, and coyotes, who largely feed on rodents. Red foxes (rare here), lynxes, and bobcats are crafty and formidable, but at best threaten only the young of large mammals. Formidable predators of a smaller scale are the many members of the weasel family, including two weasels, the badger, pine marten, wolverine and fisher (very rare here), and mink. The prey of these creatures includes many of the more familiar small mammals, such as shrews, hares, chipmunks and golden-mantled ground squirrels, Uinta ground squirrels, red and flying squirrels, mice, pocket gophers, woodrats, voles, and muskrats, and also small birds, bird eggs, reptiles, and amphibians. Porcupines and beavers are both large rodents and both feed on bark, but their defenses differ. Beavers escape to their snug lodge protected by the surrounding water, while porcupines are protected by quills. But porcupines sometimes fall prey to fishers and maybe smaller cats and other critters able to get at their unprotected faces and bellies.

Bird watchers are content here just to see the rare trumpeter swan—on the Elk Refuge, or at Christian and Hedrick Ponds. Other large birds include bald eagles, ospreys, sandhill cranes, Canada geese, and great blue herons. The water ouzel (dipper) walks underwater in fast current, a marvel to behold. Bold and brassy are the crafty magpies, who won’t hesitate to let you know if you annoy them. More than 100 species of birds have been identified in the park.

Four major natural communities provide a way of understanding the park’s wildlife patterns. The water communities include lakes, ponds, rivers, and streams. The sage and grassland community is the most extensive and most often overlooked. The forest community appears randomly distributed, but soil moisture properties, the direction it faces, elevation, and weather patterns influence where trees grow. Blue spruce and cottonwood thrive along valley streams. Aspen, Douglas-fir, and lodgepole pine inhabit the valley and lower slopes. Sub-alpine fir, Engelmann spruce, and limber pine stand on mountainsides and in canyons. The edges where communities meet are richest in wildlife. The alpine community crowning the highcountry shares the least characteristics and organisms with the other three communities.

Water communities call to mind perhaps the trout and beaver (see pages 48 and following), and lakes, ponds, streams, and rivers interrupt or dot the other three communities. In winter moose inhabit the river flats to browse the cottonwoods and willows.

The pronghorn and sage grouse characterize the wide open sage and grassland community, whose purpose otherwise seems simply to provide the Teton Range a foreground. This world is alive with small birds feeding on masses of insects and spiders. These songbirds, along with gophers, mice, and snakes, provide the diet for weasels, hawks, and ravens. The sage grouse depends largely on the evergreen sagebrush for food. The pronghorns depend on it part-time, being unable to subsist on grasses alone. This is North America’s fastest mammal, able to run at more than 45 miles per hour. For added security it boasts oversize lungs and windpipe, and the largest eyes by body weight of any mammal. Faster yet is the prairie falcon that hunts these flats, streaking out of the sky at speeds up to 200 miles per hour.

An aspen grove of only 27 trunks may shelter more than 12 pairs of birds—house wrens, mountain bluebirds, swallows, and woodpeckers. It may also shelter an understory of young spruce and fir that could one day replace it. Deer and elk wander out of the forest to browse the aspen, which can produce more than 2.5 tons dry weight of vegetation per acre. Ironically, aspen have suffered somewhat in the park for lack of forest fires. It turns out that fire suppression suppresses aspens, which recover burned areas quickly. In respect of natural processes, the park now practices wildfire management instead of complete suppression, except where human life and private property might be threatened.

The alpine world (see pages 36-37) stands as magic for some. Its lilliputian scale fascinates. A tiny rabbit, the pika (or cony), gathers grasses there all summer in miniature haystacks you may discover. The yellow-bellied marmot, on the other hand, stores fat, its body being adapted to pass the winter in hibernation. Surprising numbers of insects are found there. And spiders wander the snowfields to feed on cold-sluggish insects blown up from warmer elevations.

Diminutive alpine creatures aren’t seen from a car, but much of the park’s wildlife bounty reveals itself to casual observers. The national park tries to offer the wild community a haven where natural processes can work, but this is no simple task. The park includes only portions of some creatures’ annual ranges. And underlying the ideal balance of natural processes are complex relationships we only gradually unravel.

Mammals

Birdlife

Wildflowers