A spokeswoman for the Alaska State Troopers says a steering problem may have disabled a boat before four people were ejected into the Kenai River.
A search continues for 63-year-old Phillip Keltner of Colorado, one of the four who entered the river Friday night from the disabled boat. His hometown was not immediately available.
Keltner was last seen floating downriver. None of the four boaters wore a life jacket but the other three swam to shore.
Troopers' spokeswoman Megan Peters says she does not have details on why the boaters were ejected. The private boat did not sink.
The Kenai River is Alaska's most heavily fished river. Rainbow trout and runs of Chinook, sockeye and silver salmon draw thousands of anglers.
The 82-mile river drains the Kenai Peninsula south of Anchorage.