Nicholas Jeffrey Mostert, a 20-year-old from the Salt Lake City, Utah area, was last seen in Yellowstone National Park on June 16, 2009. Witnesses reported that he jumped from an observation deck along the rim of the Grand Canyon of the Yellowstone into the Yellowstone River. He was then swept over the 308-foot Lower Falls.
Following the incident, park officials initiated a search. Searchers in a park helicopter scoured the 20-mile-long canyon, which ranges from 800 to 1,200 feet deep.
...Read MoreLast Seen: Jun 16, 2009