https://www.usa.gov/copyrighted-government-workshttps://www.rawpixel.com/image/12168761Edit ImageSaveSaveEditCropCustom TextExamining mud from bottom of hole to determine characterisitcs of stratum through which they are drilling oil. Near Saint Louis, Oklahoma by Russell LeeView public domain image source hereMorePublic DomainFree CCO U.S. Government image for Personal and Business useInfoView CC0 LicenseEditorial use only JPEGTIFFSmall JPEG 857 x 1200 px | 300 dpiLarge JPEG 2499 x 3500 px | 300 dpiBest Quality JPEG 3059 x 4284 px | 300 dpiTIFF 3059 x 4284 px | 300 dpi | 25 MBFree DownloadExamining mud from bottom of hole to determine characterisitcs of stratum through which they are drilling oil. Near Saint Louis, Oklahoma by Russell LeeMore