Introduction to Geography of Wyoming
Wyoming in briefGeneral informationStatehood: July 10, 1890, the 44th state.State abbreviations: Wyo. (traditional); WY (postal).State capital: Cheyenne, the capital of Wyoming since 1869.State motto: Equal Rights.Popular name: The Equality State.State song: "Wyoming." Words by Charles E. Winter; music by G. E. Knapp.Symbols of WyomingState bird: Meadowlark.State flower: Indian paintbrush.State tree: Plains cottonwood.State flag and seal: Wyoming's state flag, adopted in 1917, shows the state seal on a white buffalo to represent the branding of livestock. The background is a blue background with a red border. The red border symbolizes Indians and the blood of the pioneers. On the state seal, adopted in 1893, the woman and the motto symbolize equal rights in Wyoming, the first state to grant unrestricted civil and political rights to women. A cowboy and a miner represent the state's important livestock and mining industries.Land and climateArea: 97,818 mi2 (253,349 km2), including 714 mi2 (1,848 km2) of inland water.Elevation: Highest--Gannett Peak, 13,804 ft (4,207 m) above sea level. Lowest—Belle Fourche River in Crook County, 3,100 ft (945 m) above sea level.Record high temperature: 115 °F (46 °C) at Basin on Aug. 8, 1983.Record low temperature: –66 °F (–54 °C) at Moran, near Elk, on Feb. 9, 1933.Average July temperature: 67 °F (19 °C).Average January temperature: 19 °F (–7 °C).Average yearly precipitation: 13 in (33 cm).PeoplePopulation: 493,782.Rank among the states: 50th.Density: 5 per mi2 (2 per km2), U.S. average 78 per mi2 (30 per km2).Distribution: 65 percent urban, 35 percent rural.Largest cities in Wyoming: Cheyenne (53,011); Casper (49,644); Laramie (27,204); Gillette (19,646); Rock Springs (18,708); Sheridan (15,804).EconomyChief productsAgriculture: beef cattle, hay, hogs, sheep, sugar beets.Manufacturing: chemicals, food and beverage products, petroleum products. Mining: bentonite, coal, natural gas, petroleum, trona.GovernmentState governmentGovernor: 4-year term.State senators: 30; 4-year termsState representatives: 60; 2-year termsCounties: 23.Federal governmentUnited States senators: 2.United States representatives: 1.Electoral votes: 3.Sources of informationFor information about tourism, write to Wyoming Travel and Tourism, I-25 and College Drive, Cheyenne, WY 82002. The Web site at http://wyomingtourism.org also provides information.For information on the economy, write to: Wyoming Business Council, 214 W. 15th Street, Cheyenne, WY 82002. The state's official Web site at http://www.state.wy.us also provides a gateway to much information on Wyoming's economy, government, and history.Physical Geography
LandWyoming occupies part of two great physiographic divisions of the United States: the Rocky Mountains and the Great Plains.
Ranges of the Rocky Mountains cross the state in a mainly northwest-southeast direction. In the southeast are the 10,000- to 12,000-foot (3,050- to 3,660-m) Laramie and Medicine Bow mountains, which enclose the Shirley and Laramie basins. Nearby is the Sierra Madre range. Ranges in central Wyoming are relatively low; those in the northwest rise to great heights. The Wind River Range is the loftiest and contains the state's highest mountain—Gannett Peak, 13,804 feet (4,207 m). The Bighorn Mountains, in the north, and the Absaroka Mountains, in the northwest, rise to more than 13,000 feet (3,960 m) and flank the Bighorn Basin. Most of southwestern Wyoming is part of the broad Wyoming Basin, which includes a number of smaller basins.
Near the western border is some of America's most spectacular mountain scenery. Here, the Teton Range rises majestically to more than 13,700 feet (4,175 m) in Grand Teton National Park. Other high western ranges include the Gros Ventre, Wyoming, and Salt River ranges. The varied landforms and wildlife of Yellowstone National Park, in the northwestern corner of the state, make it one of the country's greatest tourist attractions.
Most of eastern Wyoming is part of the Great Plains. The land is flat to rolling, with occasional high buttes and volcanic necks (columns of solidified lava), including Devil's Tower. In the northeast, the plains give way to the western slopes of the Black Hills.
WaterThe Continental Divide, which separates Atlantic and Pacific drainage basins, cuts the state diagonally from the Sierra Madre range to Yellowstone National Park. Most rivers west of the divide drain to the Gulf of California by way of the Green River, a tributary of the Colorado River. A small section of western Wyoming—the headwater region of the Snake, Greys, and Salt rivers—drains to the Pacific Ocean by way of the Snake and Columbia rivers. Waters north and east of the divide flow to the Gulf of Mexico by way of the Missouri-Mississippi system. Chief among these rivers are the Yellowstone, Shoshone, Wind, Bighorn. Powder, Belle Fourche, Cheyenne, North Platte, Laramie, and Sweetwater.
Of Wyoming's natural lakes, Yellowstone Lake, in Yellowstone National Park, and Jackson Lake, in Grand Teton National Park, are the largest and most scenic. There are also many snow- and glacier-fed lakes in the high mountains. Dams have created large reservoirs for irrigation, waterpower, and recreation. Among them are Flaming Gorge Reservoir, on the Green River, and Bighorn Lake, on the Bighorn River, both of which are part of national recreational areas. Other reservoirs include Pathfinder and Seminoe reservoirs, on the North Platte River; Buffalo Bill Reservoir, on the Shoshone; Boysen Reservoir, on the Bighorn; and Keyhole Reservoir, on the Belle Fourche.
There are hundreds of geysers and hot springs. These include Old Faithful geyser in Yellowstone National Park; Hot Springs, near Thermopolis; and Saratoga Hot Springs, near Saratoga.
ClimateThe Great Plains and the large western basins have a dry, sunny, continental climate. The mountains, in contrast, have a more humid, colder climate, which becomes more severe with increasing elevation.
Summers are fairly warm on the plains and in the basins. July temperatures often reach 80° to 90° F. (27° to 32° C.) during the day but drop sharply at night; they average about 60° to 75° F. (16° to 24° C.) throughout most of the state. Freezing temperatures can occur in the mountains throughout the summer months.
Winters are long and cold with occasional blizzards as well as brief periods of mild weather brought by chinook winds. January temperatures often dip considerably below 0° F. (-18° C.), but average 10° to 25° F. (-12° to -4° C.), depending on location. The coldest weather is in the mountain basins.
Most of the Great Plains receives 12 to 16 inches (306 to 406 mm) of precipitation each year; the western basins, 5 to 10 inches (127 to 254 mm). However, the total amount, both locally and for the state as a whole, is highly variable from year to year. Snowfall is heavy only in the mountains, where it reaches 200 inches (5,080 mm) a year or more.
Vegetation and WildlifeThe Great Plains of Wyoming are sparsely covered with vegetation, which consists mainly of short grasses—including buffalo and grama grasses, wheat-grass, and needlegrass—interspersed with sagebrush. With few exceptions, trees in this region grow only along the rivers; most common are willows and cottonwood. A sagebrush steppe with cacti and other drought-resistant plants prevails in the parched Wyoming and Bighorn basins.
Forests occur mainly in the mountains and cover about one-sixth of the state. The timberline lies at about 10,000 feet (3,000 m). Trees are mainly lodgepole and ponderosa pine, Engelmann spruce, Douglas fir, and other conifers. Quaking aspen grow among the conifers on lower slopes. Much of the forest land is owned by the federal government and held in national forests and parks.
The state abounds in wildlife and is particularly noted for its big game, including antelope (pronghorn), bear, deer, elk, moose, mountain sheep, and mule deer. Birds include pheasants, ducks, geese, grouse, partridge, and wild turkeys. There are almost 80 species of fish in the state's lakes and streams. Among them are trout, grayling, whitefish, pike, bass, crappie, perch, sunfish, ling, and catfish.