Details of Disappearance
Theis traveled to Montana from his hometown in Eden Valley, Minnesota in November 2003 for a vacation. He planned to collect rocks and hunt mule deer in the Upper Missouri River Breaks area. He told his mother he would be home by the end of the month if not sooner.
Theis checked into the Super 8 motel in Lewistown on November 22 and paid part of his bill in advance. He was supposed to check out on November 24, but he didn't, and he left most of his property behind in the motel. Only his rifle and hunting clothes were missing.
Theis was reported missing on November 26, two days after he failed to checked out of his motel as scheduled. A search plane found his truck parked near the Stafford Ferry on the Missouri River, with his empty rifle case and a pair of boots on the floor. No other evidence of his whereabouts was ever found.
Theis used to live near the area where he went hunting, but by 2003 he hadn't been there in a long time. He's described as an avid outdoorsman. He had worked for Geocomm, a global positioning system company, for about ten years prior to going missing and was described as a responsible employee with a good reputation.
Theis was declared legally dead eight years after his disappearance. Authorities believe he became lost in the wilderness.