Authorities searched the river Thursday night, but there was no sign of the man. Officials say he and another man were heading east on the river when they got too close to the Altoona dam and flipped over. The other man was able to swim to shore.
A witness, Steve Anderson, tells WEAU-TV the men were not wearing life jackets, but the jackets surfaced after the canoe tipped over.
Altoona fire and police departments and Eau Claire firefighters searched for the missing man.