A man drowned in the Russian River at Duncans Mills late Saturday afternoon, authorities said.

The man was one of two in a kayak that capsized just west of the Casini Ranch Campgrounds.

Witnesses who called 911 saw he was having trouble staying afloat, and then he disappeared from sight, the Sonoma County Sheriff’s Office said in a statement.

The victim, whose identity and hometown were unavailable Saturday night, was eventually pulled by bystanders from about 8 to 10 feet of water, Monte Rio Fire Chief Steve Baxman said.

The man had been underwater for an estimated 7 to 10 minutes, the Sheriff’s Office statement said.

Emergency crews who had been dispatched at 4:01 p.m. performed CPR, but the man was pronounced dead at 4:37 p.m., Baxman said.

The drowning took place where Austin Creek enters the Russian River, Baxman said.

A Casini Ranch employee said the man and his family had been staying at the campground.

Baxman said the victim appeared to be in his 20s.

You can reach Staff Writer Jeremy Hay at 521-5212 or jeremy.hay@pressdemocrat.com. On Twitter @jeremyhay.