Christopher was camping with four friends in Bath Township, Michigan on April 22, 1990. That day he went to an Earth Day celebration at Riverfront Park, then went with his friends to the remote Rose Lake Recreation Area on the campground at approximately 9:00 p.m. They had made a campfire there and Christopher walked into the surrounding woods and never returned. He has never been heard from again. An extensive search of the area turned up no indication of Christopher's whereabouts. A year and a half later, one of his sneakers was found 300 yards southwest of the campsite, in an area that had already been searched. The shoe appeared very weathered, as if it had been exposed to the elements for a long time. Investigators initially thought Christopher was a runaway, but foul play is now suspected in his disappearance.