Geologic map showing thickness of the upper Cretaceous Pierre Shale in the north half of the Powder River Basin, southeastern Montana and northeastern Wyoming
Geologic map showing thickness of the upper Cretaceous Pierre Shale in 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-2380-A Miscellaneous investigations series (Geological Survey (U.S.)) ; I-2380-A.
Variant Titles:
Thickness of the upper Cretaceous Pierre Shale, in the north half of the Powder River Basin, southeastern Montana and northeastern Wyoming, geologic map