The Great Plains meet the Rocky Mountains in Wyoming. The state is a great plateau broken by a number of mountain ranges. Surface elevations range from the summit of Gannett Peak in the Wind River Mountain Range, at 4,207 m, to the Belle Fourche River valley in the state’s northeast corner, at 952 m. In the northwest are the Absaroka, Owl Creek, Gros Ventre, Wind River and the Teton ranges. In the north central are the Big Horn Mountains; in the northeast, the Black Hills; and in the southern region the Laramie, Snowy and Sierra Madre ranges.
The Snowy Range in the south central part of the state is an extension of the Colorado Rockies in both geology and appearance. The Wind River Range in the west central part of the state is remote and includes more than 40 mountain peaks in excess of 4,000 m tall in addition to Gannett Peak, the highest peak in the state. The Big Horn Mountains in the north central portion are somewhat isolated from the bulk of the Rocky Mountains.
The Teton Range in the northwest extends for 80 km, part of which is included in Grand Teton National Park. The park includes the Grand Teton, the second highest peak in Wyoming.
The Continental Divide spans north-south across the central portion of the state. Rivers east of the divide drain into the Missouri River Basin and eventually the Atlantic Ocean. They are the North Platte, Wind, Big Horn and the Yellowstone rivers. The Snake River in northwest Wyoming eventually drains into the Columbia River and the Pacific Ocean, as does the Green River through the Colorado River Basin. The continental divide forks in the south central part of the state in an area known as the Great Divide Basin where the waters that flow or precipitate into this area remain there and cannot flow to any ocean. Instead, because of the overall aridity of Wyoming, water in the Great Divide Basin simply sinks into the soil or evaporates.
The Wind River Indian Reservation is shared by the Eastern Shoshone and Northern Arapaho tribes of Amerindians in the central western portion of the state near Lander. It is the seventh-largest Indian reservation in the United States, with a land area of 8,995.733 km², encompassing most of Fremont County. The reservation is home to 2,500 Eastern Shoshone and 5,000 Northern Arapaho. Chief Washakie established the reservation in 1868 as the result of negotiations with the federal government in the Fort Bridger Treaty. However, the Northern Arapaho were forced onto the Shoshone reservation in 1876 by the federal government after the government failed to provide a promised separate reservation.
Today the Wind River Indian Reservation is jointly owned, with each tribe having a 50% interest in the land, water, and other natural resources. The reservation is a sovereign, self-governed land with two independent governing bodies: the Eastern Shoshone Tribal Government and the Northern Arapaho Tribal Government. The Eastern Shoshone Business Council meets jointly with the Northern Arapaho Business Council as the Joint Business Council to decide matters that affect both tribes. Six elected council members from each tribe serve on the joint council.
