Montana is to the north, Nebraska and South Dakota to the east, Colorado and Utah to the south, and Idaho to the west. Rich in energy resources, Wyoming became a territory in 1868 and attained statehood on July 10, 1890. Its name derives from a Delaware Indian term meaning “at the big plains,” and its nickname, “Equality State,” was earned in 1869 when Wyoming women became the first in the United States to win the right to vote. CHEYENNE, the capital, was founded in 1867 and is one of the state’s earliest permanent settlements.
Land & Resources
Located at an average elevation of 2,042 m (6,700 ft), Wyoming is higher than any other state except Colorado. Two-thirds is occupied by rolling plains at elevations between 1,130 m (3,700 ft) and 1,860 m (6,100 ft); about one-third is part of the rugged ROCKY MOUNTAINS and rises to more than 3,000 m (10,000 ft) and in places to more than 3,900 m (13,000 ft). The plains of eastern Wyoming are broken by the prominent BLACK HILLS and Devils Tower volcanic neck and are part of the GREAT PLAINS.
The plains of the Wyoming Basin (southwestern Wyoming) and the Big Horn Basin (north central Wyoming) are similar in appearance and economy to those of the Great Plains but physiographically are part of the Rockies. The Central Rockies dominate Wyoming north and west of the Wyoming Basin and include the Big Horn Mountains and Teton, Absaroka, Wind River, Salt River, and Bear River ranges. The Laramie and Medicine Bow mountains along the southern border are part of the Southern Rockies. The CONTINENTAL DIVIDE traverses Wyoming. It divides to enclose the Great Divide Basin near Rawlins and reaches its lowest point of 2,301 m (7,550 ft) at South Pass.
Wyoming has a cool and dry climate because of its elevation and the “rain shadow effect” that causes most precipitation to fall in the mountains and leaves lowland areas with semidesert and desert conditions. Mean annual rainfall averages 305 mm (12 in) for the state as a whole but ranges from 1,016 mm (40 in) in the mountains to less than 127 mm (5 in) in the Red Desert of the Great Divide Basin. About 60% of all precipitation falls in summer.
Mean high temperatures in July reach between 29 deg C (85 deg F) and 32 deg C (90 deg F) and fall to between 10 deg C (50 deg F) and 16 deg C (60 deg F) at night, with cooler temperatures and occasional frosts in the mountains. January temperatures average minus 12 deg to minus 2 deg C (10 deg to 28 deg F). Periodic warm spells give way to cold waves and periods with below minus 18 deg C (0 deg F). The highest temperature ever recorded in Wyoming is 46 deg C (114 deg F) and occurred on July 12, 1900, at Basin; the lowest is minus 53 deg C (minus 63 deg F), recorded at Moran on Feb. 9, 1933.