Geologic and structure map of the north half of the Powder River Basin, southeastern Montana and northeastern Wyoming / U.S. Department of the Interior, U.S. Geological Survey ; by N.M. Denson, M.L. Gibson, and G.L. Sims
Series Titles:
Miscellaneous investigations series ; map I-2281-A Miscellaneous investigations series (Geological Survey (U.S.)) ; I-2281-A.