1958 Map of Keystone

About this map

Keystone stands as a primary landmark in this 1950s survey of the high mountain landscape within the Arapaho National Forest. The map documents a rugged high-altitude environment defined by sharp ridges like Keystone Mountain and deep drainages including the Snake River and Swan River. A complex network of tunnels and diversions, such as the Roberts Tunnel and Public Service Diversion, traces through the northern peaks, illustrating mid-century water management projects designed for the development of the Missouri River Basin. Higher elevations are marked by mining history, with several sites including the Saints John area, the Humboldt Mine, and Wise Mountain appearing near the glaciers and steep gulches. These details offer a record of the region's industrial and hydrological landscape before the later expansion of modern resort infrastructure.