Whalen was last seen in Glacier Park, Montana on November 2, 2000. He is a survivalist and frequented Glacier National Park, the Blackfeet tribal lands and the Columbia Falls area of Montana for several weeks during September and October 2000. Whalen's vehicle was later located at the Lake McDonald Lodge Restaurant in the vicinity of U. S. Highway 89 and State Highway 49 in Glacier Park. A park ranger found an abandoned camp at the Atlantic Creek Backcountry Campground, in Glacier Park along the North Fork of Cut Bank Creek, where personal belongings of Whalen's were identified, but there was no indication of his whereabouts at the scene and an extensive search turned up no sign of him. The circumstances surrounding his disappearance are unclear.