2015 Map of Ervay Basin

About this map

Ervay Basin and the surrounding high country of Natrona County characterize this corner of Wyoming, where the headwaters of the S Fork Powder River emerge from the high ridges. The landscape is defined by its drainage and livestock history, marked by vital water sources like Sulphur Spring and Collins Spring, as well as the Defelder Reservoir to the north. Settlement is sparse, with the community of Raderville situated in the east near the junction of Cow Camp Rd and W Poison Spider Rd. Historical transit and industry are visible in the naming of Butler Oil Rd, which skirts the Coalbank Hills. Prominent landmarks such as Maverick Butte and Cyclone Ridge provide a sense of the dramatic elevation changes that funnel toward Hoff Gap and the northern plains.