Map showing configuration and thickness, and potentiometric surface and water quality in the Madison Group, Powder River basin, Wyoming and Montana

With development of the coal resources of the Powder River Basin of Wyoming and Montana the demand for water will increase greatly. The study upon which this report is based was designed to make a preliminary evaluation of the available geo-hydrologic data for the Madison Group, which is an extensive aquifer underlying the Powder River Basin. Large yields from a few wells tapping the Madison indicate that the aquifer possibly could be utilized as one source of water for development of the coal resources of the area. 

Domestic and stock-water supplies have been developed for sandstone and coal aquifers at shallow depths in the basin, but these aquifers do not appear to be capable of supplying the large amounts of water require for coal development without endangering existing water supplies.