2021 Map of Ervay Basin

About this map

The high plains of Natrona County converge at the Ervay Basin, a landscape defined by intermittent water sources and dramatic landforms. The S Fork Powder River winds through the northern sections of the map, carving a path through the Coalbank Hills and passing through Hoff Gap. This is a territory where water management is critical for the ranching economy, as seen in the presence of Detelder Reservoir, Collins Spring, and JE Sulphur Spring. Distinctive geological features like Maverick Butte and Cyclone Ridge provide navigational landmarks in a region largely accessed by rural routes such as Butler Oil Rd and Co Rd 212. The drainage network includes Cold Camp Cr and W Deer Cr, which support the seasonal hydrologic cycle of this remote Wyoming basin.