Larsen, who lived in the 15000 block of Woodgreen Court in La Pine, Oregon, was last seen with friends in Redmond, Oregon on September 16, 2001. He and his friends had been out all night and spent part of the evening at the Fireside Grille and Lounge. Larsen had breakfast with the group at Shari's Restaurant, then left. The next morning he reportedly checked out of a hotel.

Larsen has never been heard from again. His family reported him missing eleven days after he was last seen. He was unemployed at the time of his disappearance, but he had previously worked at Hap Taylor & Sons Inc. (now called the Knife River Corporation). He has many friends and acquaintances in the Redmond area but none of them have heard from since his disappearance. He was last seen driving a white 1995 Dodge pickup with Oregon license plates numbered XTN945; the vehicle has never been located.

Larsen associated with known drug users, but investigators haven't linked any of his friends to his disappearance. Foul play is suspected in his case, which remains unsolved.