Missing Since: 2009-06-16 Location: None, Wyoming
Mostert was last seen in Yellowstone National Park on June 16, 2009. He jumped from an observation deck along the rim of the Grand Canyon of the Yellowstone, landed in the Yellowstone River and was last seen being swept over the 308-foot Lower Falls. Searchers later found some of his clothing in an eddy a quarter-mile downstream. At the time of his disappearance, Mostert was a resident of the Salt Lake City, Utah area and planned to attend the University of Utah. He enjoyed hiking, snowboarding, gardening and reading, and was a gifted writer and musician. He is presumed to have drowned. Investigating Agency Yellowstone National Park 307-344-2640 Source Information Wyoming Missing Persons The Jackson Hole News and Guide The Montana Standard The Billings Gazette The Salt Lake Tribune Updated 1 time since October 12, 2004. Last updated September 30, 2021; casefile added.