Geological Survey of OhioLibrary's c.2 mounted on cloth backing."Prepared in cooperation with Division of Labor Statistics, Department of Industrial Relations, Divisions of Mine, Department of Industrial Relations, Engineering Experiment State, The Ohio State University and State Highway Testing and Research Laboratory."by G.W. White and G.C. Gambs (with the assistance of G.R. Washburn)Scale 1:500,000 ; Lambert conformal conic projection."Base map from U.S. Geological Survey."TIFFhttps://hdl.handle.net/1811/664de8ac-bfeb-468b-9cf3-b8e196a48e58engOhio. Division of Geological SurveyPublicMines and mineral resourcesMineral industriesMineral industry map of Ohio, 1947MapsOhioThe Ohio State University