Crews are now using sonar to try and find a man missing in the Missouri River near Ponca State Park in northeast Nebraska. The Game and Parks Commission says 55-year-old Steven Bevelhymer and 49-year-old James Bevelhymer, both of Ponca, fell overboard on Saturday while trying to anchor the fishing boat. James Bevelhymer climbed back into the boat and called for help. He was treated for hypothermia. Steven Bevelhymer remains missing. Dive operations were temporarily suspended today because of unsafe conditions on the river.