https://www.usa.gov/copyrighted-government-workshttps://www.rawpixel.com/image/12301957Edit ImageSaveSaveEditCropCustom TextDr. C.K. Leith, Consultant on Minerals, Office of Production Management (OPM). Formerly professor in Geology at University of Wisconsin (still). Sourced from the Library of Congress.View public domain image source hereMorePublic DomainFree CCO U.S. Government image for Personal and Business useInfoView CC0 LicenseEditorial use only JPEGTIFFSmall JPEG 921 x 1200 px | 300 dpiLarge JPEG 2686 x 3500 px | 300 dpiBest Quality JPEG 4303 x 5607 px | 300 dpiTIFF 4303 x 5607 px | 300 dpi | 23.03 MBFree DownloadDr. C.K. Leith, Consultant on Minerals, Office of Production Management (OPM). Formerly professor in Geology at University of Wisconsin (still). Sourced from the Library of Congress.More