Castle Rock is an unincorporated community in Butte County, in the U.S. state of South Dakota.
[1] A post office called Castle Rock was established in 1910, and remained in operation until 1972.
[2] The community took its name from Castle Rock Butte.
[3] Today Castle Rock is grouped around a farm located on South Dakota Highway 79, approximately 17 miles north of Newell.
This South Dakota state location article is a stub.