Alaska State Troopers have suspended the search for an Anderson man who went missing after he apparently tried to float down the Nenana River on an air mattress, according to his family.

Arthur Hill Jr., 44, hasn’t been seen since Wednesday morning, when he was dropped off at a campsite near the Nenana River behind Anderson, according to a missing persons bulletin.

When someone checked the campsite later in the day, Hill was gone, along with his swim trunks and air mattress.

His family, who reported him missing just before 4 p.m., believes he tried to float down the river on the air mattress, troopers said.

Ken Marsh, a spokesman for the troopers, said multiple agencies and volunteer groups searched the area using boats and aircraft but turned up nothing.