Daron Duke, Far Western Anthropological Research Group project leader, carefully cleans a large spear tip before removing it from the ground at an archaeological dig site on the Utah Test and Training Range, July 13, 2016. The spear tip was one of the principle artifacts found at the site last week, and archaeologists working there believe early humans could have used it to hunt mammoths or large bison in the area thousands of years ago. (U.S. Air Force photo by Todd Cromar