21. Map showing altitude of the top of the Lakota Formation and equivalent rocks, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
22. Map showing altitude of the top of the Swift Formation, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
23. Map showing cumulative thickness of sandstone in the "Dakota Sandstone," Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
24. Map showing cumulative thickness of sandstone in the Eagle Sandstone and Telegraph Creek Formation, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
25. Map showing cumulative thickness of sandstone in the Fox Hills-Lower Hell Creek aquifer, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
26. Map showing cumulative thickness of sandstone in the Judith River Formation, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
27. Map showing cumulative thickness of sandstone in the Lakota Formation and equivalent rocks, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
28. Map showing cumulative thickness of sandstone in the Swift Formation, Montana Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading
29. Map showing outcrops of pre-Quaternary ash-flow tuffs and volcaniclastic rocks, basin and range province, Arizona Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: [Reston, Va.] : Department of the Interior, United States Geological Survey, 1984 Resource Type: Map Access & Availability: Loading
30. Map showing outcrops of pre-quaternary ash-flow tuffs and volcani-clastic rocks, basin and range province, Nevada Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Denver, Colorado : Open-File Services Section, Western Distribution Branch, U.S. Geological Survey Resource Type: Map Access & Availability: Loading