Keystone is a city in the Black Hills region of Pennington County, South Dakota, United States. The population was 240 at the 2020 census. It had its origins in 1883 as a mining town, and has since transformed itself into a resort town, serving the needs of the millions of visitors to the Mount Rushmore National Memorial, which is located just beyond the town limits. Keystone was heavily damaged in the 1972 Black Hills flood.

The town took its name from a local mine, which most likely was named after the keystone Masonic symbol.

Geography

According to the United States Census Bureau, the town has a total area of , all land.

Demographics

2010 census

At the 2010 census there were 337 people, 153 households, and 81 families living in the town. The population density was . There were 230 housing units at an average density of . The racial makeup of the town was 93.8% White, 3.3% Native American, 0.6% Asian, 0.3% Pacific Islander, 0.3% from other races, and 1.8% from two or more races. Hispanic or Latino of any race were 8.3%.

Of the 153 households 23.5% had children under the age of 18 living with them, 39.2% were married couples living together, 8.5% had a female householder with no husband present, 5.2% had a male householder with no wife present, and 47.1% were non-families. 34.0% of households were one person and 10.4% were one person aged 65 or older. The average household size was 2.20 and the average family size was 2.83.

The median age in the town was 42.8 years. 22.3% of residents were under the age of 18; 3.8% were between the ages of 18 and 24; 27.5% were from 25 to 44; 33.5% were from 45 to 64; and 12.8% were 65 or older. The gender makeup of the town was 50.7% male and 49.3% female.

2000 census

At the 2000 census there were 311 people, 152 households, and 84 families living in the town. The population density was . There were 209 housing units at an average density of . The racial makeup of the town was 95.50% White, 1.93% Native American, 0.32% from other races, and 2.25% from two or more races. Hispanic or Latino of any race were 3.54%.

<gallery>

File:Dean Franklin - 06.04.03 Mount Rushmore Monument (by-sa)-2 new.jpg|Mount Rushmore

File:National Presidential Wax Museum.jpg|The National Presidential Wax Museum, a private museum in Keystone

File:BHC RR in 2001.jpg|Black Hills Central Railroad

File:Keystone Wye Bridges.jpg|Keystone Wye just north of the town

File:Griphite-339032.jpg|Identification card of griphite mineral

File:Spodumene - large crystals in granite - Etta mine, Keystone, Pennington County, South Dakota.jpg|Crystals at the Etta Mine

File:Keystone South Dakota schools, 1895 and 1899, now a museum.jpg|Keystone schools from 1895 and 1899, now a museum

</gallery>

References

  • Keystone History