Wyoming county map

How Wyoming’s counties are laid out

Wyoming has only 23 counties for 97,813 square miles, so the average county is about 4,250 square miles — larger than Delaware and Rhode Island combined. The first county, Laramie, was created by Dakota Territory in 1867 when the Union Pacific reached Cheyenne, and the first four (Laramie, Albany, Carbon and Carter, soon renamed Sweetwater) were tall strips running the full height of the future territory from Colorado to Montana, each centred on a railroad town. Uinta was added in 1869, and Wyoming Territory then split the strips northward as ranching and mining spread: Johnson (1875), Crook and Pease (1875, Pease renamed Fremont in 1884), Sheridan, Converse and Natrona (1888), Weston and Big Horn (1890–1897).

The last big reorganisation came in 1911, when the legislature created nine counties at once — Campbell, Goshen, Hot Springs, Lincoln, Niobrara, Platte, Washakie, Sublette and Teton — though Sublette and Teton were not organised until 1923. The map has been unchanged since then. Names recall Native leaders and peoples (Washakie, the Shoshone chief; Niobrara, from the river), explorers and mountain men (Fremont, Sublette), landmarks (Big Horn, Hot Springs, Teton, Platte, Carbon for the coal beds, Sweetwater for the river, Natrona for its natron deposits) and soldiers and politicians (Sheridan, Crook, Johnson, Campbell, Converse).

Each county elects a three-member board of commissioners. Wyoming has no independent cities and no consolidated city-counties. Yellowstone National Park, in the north-west corner, is divided between Park and Teton counties; the county seats nearest to it, Cody and Jackson, are the gateways from east and south.

All 23 counties of Wyoming

Five county facts

• Largest by area: Sweetwater County, seat Green River, about 10,430 square miles of high desert, coal and trona mines in the south-west — larger than Massachusetts. Fremont, Carbon, Park and Natrona counties are also above 5,000 square miles.
• Smallest by area: Hot Springs County, seat Thermopolis, about 2,000 square miles in the Big Horn Basin, still bigger than the whole state of Delaware.
• Most populous: Laramie County, seat Cheyenne, with about 100,500 people in 2020. Natrona County (Casper) is second at about 80,000, then Campbell (Gillette), Sweetwater and Albany (Laramie), each between 38,000 and 47,000.
• Least populous: Niobrara County, seat Lusk, on the Nebraska line, with about 2,470 people — the least populous county in the least populous state.
• Oldest and newest: Laramie County (1867), created by Dakota Territory before Wyoming Territory existed, is the oldest. Sublette and Teton counties, created in 1911 but not organised until 1923, are the newest. There are no independent cities.

Reading the map

Press Streets and zoom in on the highlighted state to see county lines. Wyoming’s borders are pure latitude and longitude, and most county lines inside are straight too, drawn along survey lines rather than rivers. The four southern counties along the Union Pacific — Laramie, Albany, Carbon and Sweetwater, plus Uinta at the Utah corner — are the oldest tier; the northern tier of Park, Big Horn, Sheridan, Campbell and Crook lies along the Montana line, with Teton County and Yellowstone in the far north-west. Natrona and Fremont fill the centre around Casper and the Wind River Range. The Continental Divide crosses the state diagonally from Yellowstone to the Colorado line, splitting in Sweetwater and Carbon counties to enclose the Great Divide Basin, which drains to neither ocean. The whole state keeps Mountain Time.

Related maps

• Wyoming map — cities, borders and geography.
• Blank Wyoming map and printable Wyoming map.
• Cheyenne, the state capital, in Laramie County.
• Neighbouring county maps: Montana, South Dakota, Nebraska, Colorado, Utah, Idaho.
• Mountain states · Rocky Mountain region · Mountain Time Zone.
• Geography: Yellowstone, Rocky Mountains, Continental Divide, Snake River.
• All US county maps.