Map of Dewey County, South Dakota

Dewey County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 5,239. Its county seat is Timber Lake. The county was created in 1883 and organized in 1910. It was named for William P. Dewey, Territorial surveyor-general from 1873 to 1877.

Almost the entire county lies in the Cheyenne River Indian Reservation. The balance of the county, along its extreme northern county line, lies in the Standing Rock Indian Reservation. It is one of five South Dakota counties that are contained within Indian reservations.

Dewey County overview:
Name:Dewey County
FIPS code:46-041
State:South Dakota
Founded:1873
Named for:William P. Dewey
Seat:Timber Lake
Total Area:2,445 sq mi (6,330 km²)
Land Area:2,302 sq mi (5,960 km²)
Total Population:5,239
Population Density:2.1/sq mi (0.83/km²)
Time zone:UTC−7 (Mountain)
Summer Time Zone (DST):UTC−6 (MDT)

Dewey County location map. Where is Dewey County?

Dewey County location on the U.S. Map. Where is Dewey County.
Location of Dewey County in the the United States.
Dewey County location on the South Dakota map. Where is Dewey County.
Location of Dewey County in South Dakota.

Dewey County Road Map

Dewey CountyStreet Map.
Street map of Dewey County, South Dakota. Source: OpenStreetMap (OSM)
Dewey CountyMap
Dewey Countypolitical map.

Geography

The Moreau River flows east-northeasterly through the upper central parts of Dewey County, discharging into the Missouri River near the county’s NE corner. Smaller drainages move runoff water northward from the central-eastern portions to the Missouri River, discharging near the community of Promise. A significant arm of the Missouri River forms the county’s southeastern border. The county terrain consists of rolling hills, sloping southeastward and dropping off into the Missouri River basin.

The county has a total area of 2,445 square miles (6,330 km), of which 2,302 square miles (5,960 km) is land and 143 square miles (370 km) (5.8%) is water.

The eastern portion of South Dakota’s counties (48 of 66) observe Central Time; the western counties (18 of 66) observe Mountain Time. Dewey County is the easternmost of the SD counties to observe Mountain Time.

Major highways

  • U.S. Highway 212
  • South Dakota Highway 20
  • South Dakota Highway 63
  • South Dakota Highway 65

Adjacent counties

Protected Areas

  • Firesteel Dam State Game Production Area
  • Isabel Lake State Game Production Area
  • Little Moreau State Game Production Area
  • Little Moreau State Recreation Area

Lakes

  • Lake Isabel
  • Lake Oahe (partial)
  • Little Moreau Lake

Dewey County Topographic Map

Topographic Map of Dewey County, South Dakota
Dewey County Topo map.

Dewey County Satellite Map

Satellite Map of Dewey County, South Dakota
Dewey County satellite map.

Dewey County Outline Map

Outline Map of Dewey County, South Dakota
Dewey County outline map.
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Parent Unit Map

Map of United States
The United States (US) covers a total area of 9,833,520 sq. km. Of this area, the 48 contiguous states and the District of Columbia cover 8,080,470 sq. km. The archipelago of Hawaii has an area of 28,311 sq. km while the remaining area is part of the US territories. The greatest east-west distance in the ... Read more
Map of United States
Political map of South Dakota State – Printable Collection
South Dakota (/- dəˈkoʊtə/ (listen); Sioux: Dakȟóta itókaga, pronounced [daˈkˣota iˈtokaga]) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large portion of the population with nine reservations ... Read more
Political map of South Dakota State – Printable Collection

Related Administrative Divisions

Sub-Administrative Units Maps