SWAN VALLEY -- Authorities say a California man has drowned while kayaking down the South Fork of the Snake River in southeast Idaho.

The Jefferson County Sheriff Department identified the man as Patrick Luther Smith, 71, of Fresno, Calif.

Investigators say Smith drowned Thursday while kayaking the river with Lennie Hill, 72, of Rigby.

Authorities say their kayaks became swamped on a river channel near Twin Bridges.

Hill managed to swim to shore and call for help, but police say Smith was unable to get out of the water.

An angler fishing downstream later called authorities after spotting Smith's body snagged in a tree.

The accident remains under investigation.