1985 Map of Thompson Coulee

About this map

Knox Ridge and Snell Ridge dominate this Fergus County landscape, defining the complex drainage patterns of the Missouri River basin. This 1985 provisional study captures a topography shaped by seasonal watercourses and deep coulees, where Armells Creek and its tributary Dry Armells Creek wind through the breaks. The network of winding drainages like Sourdough Creek and Sawmill Coulee reflects a classic Montana ranching environment, where water access dictated the placement of unimproved roads and trails. The map serves as a detailed record of land use and natural drainage prior to modern digital updates, preserving the specific nomenclature of features like Antelope Coulee and Thompson Coulee that define this interior plateau.