The State of Wyoming ( ) is a sparsely populated state in the western region of the United States. The majority of the state is dominated by the mountain ranges and rangelands of the Rocky Mountain West, while the easternmost section of the state is a high altitude prairie region known as the High Plains. While the tenth largest U.S. state by size, Wyoming is the least populous, with a U.S. Census estimated population of 522,830 in 2007, a 5.9% increase since 2000. The capital and the most populous city of Wyoming is Cheyenne.

Location and size

Wyoming is bordered on the north by Montana, on the east by South Dakota and Nebraska, on the south by Colorado, on the southwest by Utah, and on the west by Idaho. It is the tenth largest state in the United States in total area, containing 97,818 square miles (253,348 km²) and is made up of 23 counties. From the north border to the south border it is 276 miles (444 km); and from the east to the west border is 375 miles (603 km).

Mountain ranges

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 13,804 feet (4,207 m), to the Belle Fourche River Valley in the state's northeast corner, at 3,125 feet (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 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 50 miles (80 km) and represents the most impressive section of mountains in the state. It is home to Grand Teton, the second highest peak in Wyoming, and to Grand Teton National Park, which preserves the most scenic section of the Teton range.

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.