Natalie miraculously survived a fatal car crash by clinging to a tree for 12 hours.

A California teenager clung to a tree in freezing waters for 12 hours to avoid being swept away after her car plunged into a creek and claimed the life of her best friend.

In an incredible story of survival, Natalie Griffin, 19, managed to escape the car through a broken back window after it hydroplaned and veered off a highway into fast-moving Outlet Creek, about three hours north of San Fransisco, on Wednesday evening.

Tragically, her friend Jenna Santos could not escape the vehicle despite Natalie’s efforts to save her and drowned, the East Bay Times reports.

Giving details of the crash, which happened about 7.30pm, Natalie’s cousin Monica Keyser said as water streamed into the car the women tried unsuccessfully to kick out the windshield.

That’s when Natalie noticed the window at the back of the car was broken.

“She told Jenna to come back that way,” Monica said. “Natalie thinks her foot got stuck.”

The river’s strong current swept Natalie to a nearby tree, which she clung to throughout the night as temperatures dropped to -2 degrees.

“She said she stayed really calm,” Monica told the newspaper.

“She was hallucinating and hearing Jenna talking, telling her she was going to be OK. There were points where she thought Jenna was with her. She remembers thinking they found a phone.”

In the morning Natalie managed to swim to shore. She climbed a hill to reach the highway and flagged down a passing car, whose driver reportedly nearly mistook her for a hitchhiker.

She was taken to a nearby hospital suffering hypothermia, but was released later that day.

About 8.20am Thursday local emergency services were called to the creek and began the search for the Jenna and the car.

The girl's vehicle was pulled from the water about 4pm and Jenna’s body was found inside the car.

The friends, who went to Castro Valley High School together, had been travelling to the East Bay, back from a trip to Humboldt County, where Jenna was a student at Humboldt State University.

Natalie and Monica have since created a GoFundMe page to help pay for Jenna's funeral costs.

"Prior to the accident Jenna told Natalie that although short, this had been the best trip of her life," Monica wrote.

"She will forever be remembered for her contagious smile, kind heart, and her ability to light up any room."