For your consideration are these two Geological Atlases of the United States featuring two Montana locations, Philipsburg and Butte. The first atlas is for Philipsburg, Montana and was made in 1915 by F. C. Calkins and W. H. Emmons. The atlas includes colored map sheets, tables, illustrations, topography maps and more. The atlas is set in plastic wrap and sits on a foam board to remain flat. The atlas is in good condition with no signs of obvious damage. The atlas measures 21 3/4" L x 18 1/2" W. The second atlas in this collection is the Butte Special Folio done in 1897 and made by W. H. Weed. In the atlas, Weed provides a detailed description on topics such as the topography, geology, stratigraphy, structural geology and more within the famous Butte copper mining district. This atlas shows a little more wear to the edges of the pages with slight tears and creases, but overall remains in good condition. The atlas measures 21 3/4" L x 18 1/2" W.