Craigg, S.D., Dam, W.L., Kernodle, J.M., and Levings, G.W., 1989, Hydrogeology of the Dakota Sandstone in the San Juan structural basin, New Mexico, Colorado Arizona, and Utah: U.S. Geological Survey Hydrologic Investigations Atlas HA-0720-I, 2 sheets, scale 1:1,000,000.