ORONO – After nearly four hours of searching the banks and waters of the Stillwater River, rescuers called off their effort to find a 49-year-old man Monday night but were expected to resume the search early this morning.

The man last was seen swimming near the Theta Chi fraternity house. His clothing was found stacked on the riverbank. Searchers also found his footprints leading to the water, but nothing to indicate the man left the water.

The man had gone swimming with his dog about 5 p.m. but the dog returned home, wet and without his master, prompting friends to go look for him and then call for help, according to police and fire officials.

The man swims there regularly and was seen there by someone fishing in the area, reported Orono Fire Chief Lorin LeCleire. Police Chief Al Dravidzius said that there was no note and nothing to indicate a suicide.

Searchers scoured the muddy east and west banks of the river, but found no prints or anything to suggest he got out of the water, the fire chief said. Four boats, two from the Penobscot Nation, one from Orono and another from Dirigo Search and Rescue were put in the water, and searchers used a grid pattern to look for his body.

Meanwhile, divers from the Penobscot County Technical Response Team made sweeping searches in the murky waters, well into darkness looking for the man. Visibility was only about 2 to 3 feet into the water, the divers reported.

The search was called off about 9:30 p.m. and was expected to resume at 5 a.m. today with LeCleire looking to enlist the help of a National Guard helicopter to scan from well above the river, which he said was shallow and reached only about 8 feet deep. Monday night’s search operation was staged at the University of Maine’s steam plant, downriver from where the man’s hat, boots and other clothing were found.