Deerfield Dam and Reservoir, Rapid Valley Project, are twenty-five miles west of Rapid City, South Dakota on Castle Creek. Reservoir contains 400 surface acres and has 16 miles of shoreline. Public use area, camping, picnic areas, concession, swimming, boating, hiking, and fishing. Available species include rainbow trout, brown trout, and rock bass. Open year-round. Current Reservoir Levels.

Site is 25 miles west of Rapid City.