South Dakota county map

How South Dakota’s counties are laid out

South Dakota’s 66 counties cover 77,116 square miles, an average of about 1,170 square miles each — but the average hides a sharp split. East of the Missouri River the counties are small, regular squares laid out on the land survey in the 1870s and 1880s as railroads brought homesteaders; west of the river they are large, irregular and thinly settled, several of them coinciding with Indian reservations. The first counties were created by the Dakota Territory legislature in 1862 along the Big Sioux and Missouri rivers: Minnehaha, Union, Clay, Yankton, Bon Homme and their neighbours in the south-east corner, which is still where most people live.

Names come from the Sioux and their bands (Minnehaha, Yankton, Oglala Lakota, Brule), from territorial and state politicians (Beadle, Kingsbury, Hand, Hughes, Jerauld, Spink, Ziebach), from presidents and generals (Grant, Lincoln, Custer, Meade, Harding) and from home states of settlers. Two counties, Todd and Oglala Lakota, have no county seat of their own because they are unorganised: their business is handled by neighbouring Tripp and Fall River counties respectively, so the seats shown for them are administrative arrangements rather than county courthouses.

Shannon County, covering most of the Pine Ridge Reservation, was renamed Oglala Lakota County in 2015 — the most recent change to the map. Two former counties, Armstrong and Washabaugh, were absorbed by Dewey (1952) and Jackson (1983). South Dakota has no independent cities and no consolidated city-counties. Pierre, the capital, is the seat of Hughes County on the east bank of the Missouri.

All 66 counties of South Dakota

Five county facts

• Largest by area: Meade County, seat Sturgis, about 3,470 square miles stretching from the northern Black Hills across the plains to the Cheyenne River. Butte, Perkins and Harding counties in the north-west corner are also above 2,400 square miles.
• Smallest by area: Clay County, seat Vermillion, about 410 square miles on the Missouri in the south-east corner; it is home to the University of South Dakota.
• Most populous: Minnehaha County, seat Sioux Falls, with about 197,000 people in 2020 — more than one in five South Dakotans. Pennington County (Rapid City) is second at about 109,000, then Lincoln County, the fast-growing southern suburb of Sioux Falls.
• Least populous: Jones County, seat Murdo, on the plains west of the Missouri, with fewer than 1,000 people — one of the ten least populous counties in the United States.
• Oldest and newest: the 1862 territorial counties of the south-east, including Minnehaha, Union, Clay, Yankton and Bon Homme, are the oldest. The newest name is Oglala Lakota County (2015); the last boundary change was Jackson County absorbing Washabaugh in 1983. There are no independent cities.

Reading the map

Press Streets and zoom in on the highlighted state to see county lines. The Missouri River, running diagonally from the North Dakota line to the Nebraska corner, is the key to the map: it separates the neat grid of “East River” from the big ranching counties of “West River”, and it also approximates the time-zone boundary. The counties along and east of the river keep Central Time, while the western counties, including Pennington (Rapid City), Meade, Lawrence and the Black Hills, keep Mountain Time. The boundary does not follow the river exactly — several river counties are wholly in one zone, so check locally. The Black Hills counties of Lawrence, Pennington and Custer stand out in the south-west, and the straight northern, eastern and western borders give the state its near-rectangular outline.

Related maps

• South Dakota map — cities, borders and geography.
• Blank South Dakota map and printable South Dakota map.
• Pierre, the state capital, in Hughes County.
• Neighbouring county maps: North Dakota, Minnesota, Iowa, Nebraska, Wyoming, Montana.
• West North Central states · Great Plains · Central and Mountain time zones.
• Geography: Missouri River, Great Plains, National parks.
• All US county maps.