The sports utility vehicle driven by Christian Lemler, 50, carrying his wife and three daughters, went off Highway 50 in the Sierra Nevadas in the town of Placerville, Calif., about 75 miles northeast of Sacramento, Calif., Thursday.
The vehicle struck a concrete mile marker, a tree and a boulder before coming to rest on its side in the river, police told the Contra Costa (Calif.) Times.
A kayaker identified as Mark Divittorio, 42, by KCRA-TV, Sacramento, said he helped the three girls first, then returned for Lemler and his wife. Christian Lemler was the most seriously injured, but is expected to make a full recovery, police said.
The cause of the crash remains under investigation, but police said rain and slick road conditions are the likely cause.