Kurt was last seen on September 1, 1975, at the remote Natanis Point Campground in Chain of Ponds, Maine, approximately six miles from the Canadian border. He was camping with his parents, older sister, and three other families from their hometown of Manchester, Maine.

Kurt vanished between 10:00 and 10:30 a.m. while riding his Big Wheel tricycle near the family's campsite. Later that morning, his tricycle was discovered at a dump site about eight-tenths of a mile from where his family was camping.

At the time of his disappearance, Kurt was described as very shy and reluctant to be separated from his mother, even briefly. He had no history of wandering off without permission, and his parents did not believe he would have entered the woods alone.