1955 Map of Dillon

About this map

The Continental Divide snake through this expansive mid-century survey of southwest Montana and eastern Idaho, marking the high crest of the Beaverhead Mountains and Anaconda Range. The landscape is dominated by the sprawling headwaters of the Missouri River system, where the Big Hole River and Beaverhead River carve wide valleys between the Pioneer Mountains and the Ruby Range. Historic mining and pioneer settlements like Bannack and Argenta sit tucked into the foothills, while the town of Dillon serves as a central hub for the Union Pacific rail lines and regional roads. To the west, the Big Hole Battlefield Nat Mon preserves the site of the 1877 conflict within the Big Hole basin. Large-scale water management is evident in the presence of the Ruby River Reservoir and the Clark Canyon Reservoir, reflecting the region's long-standing reliance on irrigation and ranching.