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.
Shaped like a short-handled dipper, the Snake River progresses westward through the nation’s largest chunk of wilderness outside Alaska. The Snake’s drainage also figured in historic exploring expeditions and scientific, military, and railroad route surveys during the 19th century. Some important expedition and survey routes are shown on this map.
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Expeditions and Trappers
“Beaver Flats”
“John Colter Visits the Crows 1807”
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.
Codsiogo, a Shoshone warrior.
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.
A Sheepeater Indian family.
Cutthroat Trout
An osprey landing on its nest.
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.
Mule deer, named for their large ears, occur in surprisingly small numbers in the park. Competition with the large elk herd and deep winter snows may be limiting factors.