Oacoma is a town in Lyman County, South Dakota, United States. The population was 386 at the 2020 census. Oacoma is located on the west bank of the Missouri River, across from Chamberlain, South Dakota.
History
thumb|upright|Al's Oasis, a stopping-off place in Oacoma along Interstate 90
On September 17, 1804, Lewis and Clark camped on the west bank of the Missouri River near American Island where Oacoma is now located. During the remainder of the 19th century the area was a stopping off place for explorers, fur traders and steamboat men. The township of Oacoma was laid out in 1891 as the county seat for the newly formed Lyman County; the County seat was transferred to the town of Kennebec in 1922. The Chicago, Milwaukee, St. Paul and Pacific Railroad arrived in Oacoma in 1905, and Oacoma was known as a "banking post-village". In the 21st century, it is a rest stop for travelers on Interstate 90.
Geography
According to the United States Census Bureau, the town has a total area of , of which is land and is water.
American Crow Creek, a tributary to the Missouri River, enters the Missouri River in Oacoma.
The town is located approximately halfway between Sioux Falls and Rapid City.
Demographics
2010 census
As of the census of 2010, there were 451 people, 205 households, and 135 families residing in the town. The population density was . There were 236 housing units at an average density of . The racial makeup of the town was 88.9% White, 0.2% African American, 6.4% Native American, 0.4% Asian, 0.7% from other races, and 3.3% from two or more races. Hispanic or Latino of any race were 1.8% of the population.
There were 205 households, of which 27.8% had children under the age of 18 living with them, 52.7% were married couples living together, 8.3% had a female householder with no husband present, 4.9% had a male householder with no wife present, and 34.1% were non-families. 30.2% of all households were made up of individuals, and 9.3% had someone living alone who was 65 years of age or older. The average household size was 2.20 and the average family size was 2.64.
The median age in the town was 44.3 years. 19.7% of residents were under the age of 18; 7.4% were between the ages of 18 and 24; 24.1% were from 25 to 44; 33.4% were from 45 to 64; and 15.3% were 65 years of age or older. The gender makeup of the town was 52.5% male and 47.5% female.
2000 census
As of the census