Mountain Plains, SD

Mountain Plains is a Lawrence County CDP on the northern edge of the Black Hills, just north of Spearfish. U.S. 14A forms its eastern edge as it follows Spearfish Creek through the canyon, giving this small unincorporated place a very specific boundary: highway on one side, creek and Black Hills terrain on the other. Mountain Plains first appeared as a CDP before the 2020 census and counted 327 people that year. The community is in Spearfish School District 40-2. Mountain Plains is a foothills address, a school district, and a narrow South Dakota map where the creek does most of the organizing.