Atlas D Missile Site 4 located in Laramie County, Wyoming is a Formerly Used Defense Site (FUDS), previously under the command of F.E. Warren Air Force Base. The U.S. Army Corps of Engineers, Omaha District, is managing the environmental cleanup resulting from former activities at the site that have contaminated the groundwater with trichloroethene (TCE), a cleaning solvent. The site is located approximately 18 miles west of Cheyenne and one mile south of the town of Granite, Wyoming.