It happened about three miles away from the Mercey Hot Springs resort located on Little Panoche Road around 6 am Saturday.
The California Highway Patrol says three people were in a modified Jeep when they started rolling backwards while trying to go up a hill on unpaved road.
The Jeep ultimately rolled over, and all three people were thrown from it. Officers say there were no seatbelts since the vehicle was modified.
One of the passengers died from their injuries. The other passenger climbed down the hill while injured to call 911.
The driver was airlifted to the hospital with major injuries.
The identity of the person killed has not been released.