1951 Map of Twentyone Divide

About this map

The Cheyenne River carves through the landscape of the Wyoming and South Dakota border, a region defined by its complex drainage systems and high ridges. In the early 1950s, this area served as a remote intersection of ranching and early transit infrastructure, where the Chicago Burlington and Quincy railroad line tracks across the northeastern corner. The local community is anchored by the Cheyenne River School, a vital social and educational landmark for the scattered population living near Twentyone Divide. To the north, Beaver Creek and Lone Tree Creek feed into the river system, while an Artesian Well indicates the essential reliance on groundwater in this arid environment. The map also captures the edge of the Harney National Forest, providing a detailed look at the public lands and county boundaries where Niobrara, Fall River, and Custer Counties meet along the Black Hills Meridian.