Police said officers were told of the Clearwater River incident at about 10:15 p.m. on Sunday night.
“Witnesses observed a male wearing a life-jacket floating in the turbulent river but were unable to make contact with him and called police,” the RCMP said in a news release. “The male was last seen in the water approximately 28 miles west of the Clearwater Bridge, near Highway 22 and Highway 591.”
The RCMP said officers found a vehicle and boat trailer in the area and “have not been able to contact the 34-year-old male registered owner from Calgary.”
“Police believe the owner of the vehicle and trailer are the same male that was observed in the water,” police said.
“RCMP and emergency services have not been able to gain access to the water due to the strong current and river debris.”
Police said an RCMP helicopter arrived Monday morning to help search the river but crews have not been able to locate the man or the boat.
The incident marks the third possible drowning that RCMP are looking into in Alberta this long weekend.
At about 8 p.m. on Sunday, Okotoks RCMP responded to the Highwood River for a report of a missing swimmer. The swimmer reportedly jumped in the water, went under and did not resurface.
Earlier that evening, at 7:17 p.m., Lake Louise RCMP were called to Herbert Lake after a man reportedly fell into the water while paddleboarding and did not resurface.