The name "Tetons" originally was intended to describe several hills near the town of Arco, Idaho. They were named by a French trapper who thought that they resembled the female body. (Ergo tétons, the French word for "nipples" or "teats".) Many years later the name was mistakenly applied to the mountains of present day Grand Teton National Park due to poor map-making/map-reading standards of the time.
There are nearly 200 miles (320 km) of trails for hikers to enjoy in Grand Teton National Park.
Jackson Hole is a 55 mile (90 km) long by 6 to 13 mile (10 to 20 km) wide graben valley that has an average elevation of 6,800 ft (2,070 m) with its lowest point near the south park boundary at 6350 ft (1,935 m). The valley sits east of the Teton Range and is vertically displaced downward 30,000 ft (9,100 m) from corresponding rock layers in it, making the Teton Fault and its parallel twin on the east side of the valley normal faults with the Jackson Hole block being the hanging wall and the Teton Mountain block being the footwall. Grand Teton National Park contains the major part of both blocks. A great deal of erosion of the range and sediment filling the graben, however, yields a topographic relief of only up to 7,700 ft (2,350 m).
The glaciated range is composed of a series of horns and arêtes separated by U-shaped valleys headed by cirques and ended by moraines, making the Tetons a textbook example of alpine topography. Rubble piles left by ice age alpine glaciers impounded a series of interconnected lakes at the foot of the range (Jackson, Leigh, String, Jenny, Bradley, Taggart, and Phelps). The largest lake in the valley, Jackson Lake, was impounded by a recessional moraine left by a very large valley glacier as it retreated north out of Jackson Hole. Jackson Lake covers 25,540 acres (103.4 km²) and has a maximum depth of 438 feet (134 m). There are also over 100 alpine and backcountry lakes.
Just to the south is Burned Ridge, the same glacier's terminal or end moraine, which runs down the center of Jackson Hole roughly perpendicular to the range and cut in two by the Snake River. After exiting its dammed outlet at the southeast corner of Jackson Lake, the Snake runs down the valley and through the 10 mile (16 km) long glacial outwash plain south of Burned Ridge. The river's headwaters are in a part of the Teton Wilderness a short distance north in Yellowstone National Park and its destination is the Columbia River far to the west, which in turn empties into the Pacific Ocean. Terraces have been cut by the river into the moraines and outwash plain in the valley. About 50 miles (80 km) of the 1,056 miles (1,699 km) mile long Snake River winds through the park where it is fed by three major tributaries; Pacific Creek, Buffalo Fork, and the Gros Ventre River.
The local climate is a semi-arid mountain one with a yearly extreme high of 93 °F (34 °C) and extreme low of −46 °F (−43 °C). Average annual snowfall is 191 inches (490 cm) and average rainfall is 10 inches (250 mm). The coldest temperature ever recorded in Grand Teton National Park was −63 °F (−52 °C), and snow often blankets the landscape from early November to late April.
The Tetons were named by French explorers who called the three highest peaks of the range Les Trois Tetons (the three breasts). In the 18th and 19th centuries, Caucasian fur trappers and fur traders called deep valleys rimmed by high mountains "holes." One such fur trapper was named David Jackson and his favorite place to 'hole-up' was named after him in 1829.
John Colter, a member of the Lewis and Clark Expedition, is the first white American known to have visited the area now know as Jackson Hole as early as 1805-1806. Geologist F.V. Hayden visited the area in 1860 as part of the Raynolds expedition. In the summer of 1871 he led the first government-sponsored scientific survey of the Yellowstone area just to the north. One part of that survey, led by geologist James Stevenson, traveled into Jackson Hole via the Teton Pass before meeting up with the other half of the expedition in Yellowstone. While passing through, the team, which included Yellowstone's first superintendent N.P. Longford, photographer William Henry Jackson, and artist William Henry Holmes, among others, mapped the area and surveyed its geology and biology. These data were later included in the Hayden Survey set of reports.
Homesteaders moved into Jackson Hole after the reports were published but the short growing season along with weeks of being snowed-in each winter kept all but the hardiest individuals away. One of those settlers, a rancher named Pierce Cunningham, circulated a petition to have Jackson Hole saved for the "education and enjoyment of the Nation as a whole."
Local attitudes started to change that same year when proposals to dam Jenny, Emma Matilda, and Two Ocean lakes surfaced. Then on July 26 1923, local and Park Service representatives including Albright met in Maud Noble's cabin to work on a plan to buy private lands to create a recreation area to preserve the "Old West" character of the valley. Albright was the only person who supported Park Service management; the others wanted traditional hunting, grazing, and dude-ranching activities to continue. In 1927 philanthropist John D. Rockefeller, Jr. founded the Snake River Land Company so he and others could buy land in the area incognito and have it held until the National Park Service could administer it. The company launched a campaign to purchase more than 35,000 acres (142 km²) for $1.4 million but faced 15 years of opposition by ranchers and a refusal by the Park Service to take the land.
In 1928, a Coordinating Commission on National Parks and Forests met with valley residents and reached an agreement for the establishment of a park. Wyoming Senator John Kendrick then introduced a bill to establish Grand Teton National Park. It was passed by both houses of the U.S. Congress and signed into law by U.S. President Calvin Coolidge on February 26 1929. The 96,000 acre (388 km²) park was carved from Teton National Forest and included the Teton Range and six glacial lakes at its foot in Jackson Hole. Lobbying by cattlemen, however, meant that the original park borders did not include most of Jackson Hole (whose floor was used for grazing). Meanwhile the Park Service refused to accept the 35,000 acres (142 km²) held by the Snake River Company.
Discouraged by the stalemate, Rockefeller sent a letter to then U.S. President Franklin D. Roosevelt telling him that if the federal government did not accept the land that he intended to make some other disposition of it or to sell it in the market to any satisfactory buyers. Soon afterward on March 15 1943 the president declared 221,000 acres (894 km²) of public land as Jackson Hole National Monument. Continued controversy over the Rockefeller gift still made it impossible for the monument to officially include that land, however.
Opposition to the monument by local residents immediately followed with criticism that the declaration was a violation of states' rights and that it would destroy the local economy and tax base. Ranchers drove 500 cattle across the newly created monument in a demonstration designed to provoke conflict. The Park Service did not respond to the stunt but the event brought national attention to the issue nonetheless. Wyoming Representative Frank A. Barrett introduced a bill to abolish the monument that passed both houses of Congress but was pocket vetoed by Roosevelt. U.S. Forest Service officials did not want to cede another large part of the Teton National Forest to the Park Service so they fought against transfer. One final act was to order forest rangers to gut the Jackson Lake Ranger Station before handing it over to park rangers. Residents in the area who supported the park and the monument were boycotted and harassed.
Other bills to abolish the monument were introduced between 1945 and 1947 but none passed. Increases in tourism money following the end of World War II has been cited as a cause of the change in local attitudes. A move to merge the monument into an enlarged park gained steam and by April, 1949, interested parties gathered in the Senate Appropriation Committee chambers to finalize a compromise. The Rockefeller lands were finally transferred from private to public ownership on December 16 1949, when they were added to the monument. A bill merging most of Jackson Hole National Monument (except for its southern extent, which was added to the National Elk Refuge) into Grand Teton National Park was signed into law by President Harry S. Truman on September 14 1950. One concession in the law modified the Antiquities Act, limiting the future power of a president to proclaim National Monuments in Wyoming. The scenic highway that extends from the northern border of Grand Teton National Park to the southern entrance of Yellowstone National Park was named the John D. Rockefeller, Jr. Memorial Parkway to recognize Rockefeller's contribution to protecting the area. In 2001, the Rockefellers donated their Jackson Hole retreat, the JY Ranch, to the national park for the establishment of the Laurance S. Rockefeller Preserve, dedicated on June 21, 2008.
The rock units that make up the east face of the Teton Range are around 2500 million years old and made of metamorphosed sandstones, limestones, various shales, and interbeded volcanic deposits. Buried deep under Tertiary volcanic, sedimentary, and glacial deposits in Jackson Hole, these same Precambrian rocks are overlain by Paleozoic and Mesozoic formations that have long since been eroded away from atop the Tetons.
The Paleozoic-aged sediments were deposited in warm shallow seas and resulted in various carbonate rocks along with sandstones and shales. Mesozoic deposition transitioned back and forth from marine to non-marine sediments. In later Mesozoic, the Cretaceous Seaway periodically covered the region and the Sierran Arc to the west provided volcanic sediments.
A mountain-building episode called the Laramide orogeny started to uplift western North America 70 million years ago and eventually formed the Rocky Mountains. This erased the seaway and created fault systems along which highlands rose. Sediment eroded from uplifted areas filled-in subsiding basins such as Jackson Hole while reverse faults created the first part of the Teton Range in the Eocene epoch. Large Eocene-aged volcanic eruptions from the north in the Yellowstone-Absaroka area along with later Pleistocene-aged Yellowstone Caldera eruptions, left thick volcanic deposits in basins.
The Teton Range started to grow along a north-south trending fault system next to Jackson Hole some 9 million years ago in the Miocene epoch. Then starting in the Pliocene, Lake Teewinot periodically filled Jackson Hole and left thick lakebed sediments. The lake was dry by the time a series of glaciations in the Pleistocene epoch saw the introduction of large glaciers in the Teton and surrounding ranges. During the Last Glacial Maximum, these glaciers melded together to become part of the Wisconsin glaciation, which carried away all soil from Jackson Hole and surrounding basins. Later and less severe ice ages created enough locally-deposited dirt in the form of moraines and till to repair much of this damage. Since then, mass wasting events such as the 1925 Gros Ventre landslide, along with slower forms of erosion, have continued to modify the area. On the floor of the Jackson Hole valley rise several landforms, one of the most conspicuous being Blacktail Butte.
Grand Teton National Park and areas adjacent to it host over 1000 species of vascular plants. Whitebark Pine, Limber Pine, Subalpine fir, and Engelmann Spruce survive in Tetons' alpine zone up to around 10,000 feet (~3000 m). Lodgepole Pine, Douglas Fir, and Blue Spruce are found on the valley floor, while the aspens, cottonwoods, alders, and willows commonly inhabit the moist soils along rivers and lakeshores.
Forests in the Teton area generally consist of two to three different tree species that grow together in a specific habitat. Edge habitat for various wildlife species is created where these different forest types merge in zones called ecotones. Some animals, such as the Red squirrel, pine marten, and black bear spend a majority of their life in forests. Other animal species, such as moose, elk (also known as the wapiti), and wolves, use the forest for shade and shelter in the day and move to sagebrush dominated areas or meadows to feed in the early mornings and evenings.
Soil conditions, the amount of water, slope, aspect, and elevation all help determine where different plant communities grow. Biologists divide the plants of Grand Teton National Park into these communities: forests, sagebrush flats, riparian corridors and wetlands, and alpine areas.
Evergreen forests in the area are composed of 7 species of coniferous tree while over 900 flowering plant species dominate the Teton Range below the tree line down to the top of Jackson Hole's moraines. These moraines are composed of compact piles of unsorted rubble that have good clay content and retain moisture better than the quartzite-rich outwash plain, which allows them to support large stands of Lodgepole Pines and many other plants.
Outwash plain areas are covered in a loose soil that doesn't hold moisture well and is therefore only able to support sparse vegetation such as sagebrush and coarse grasses. Numerous aspens, cottonwoods, and willows grow along in riparian zones outside of the outwash plain. Grasses, sedges, and wildflowers dominate in wet meadows.
Coyotes and badgers dig burrows into the loesses, which were blown into the valley between ice ages. High alpine areas of the park support plants that are specially adapted to the harsh conditions. These hardy plants cope with wind, snow, a lack of soil, increased ultraviolet radiation, rapid and dramatic temperature shifts, and a short growing season. Growing close to the ground in mats like the Alpine Forget-me-not is a common adaptation.
Grand Teton National Park is located in the heart of the Greater Yellowstone Ecosystem, one of the largest intact temperate zone ecosystems remaining on the planet. This means that many of the animals in the Teton area travel between the two parks and the numerous adjacent National Forests.