None of the injuries was serious, said Amtrak spokeswoman Brenda Follmer.
The 16-car Coast Starlight was traveling from Seattle to Los Angeles when it derailed just before 2 a.m. north of Dunsmuir, near Mount Shasta.
Five cars left the tracks, Follmer said. Both engines landed on their sides, while a baggage car, a crew dorm car and a passenger car derailed but did not fall over.
There were 134 passengers and 19 crew members on board. Early reports indicated that the most serious injury was to the train's engineer, who may have cracked ribs, she said.
"It was a hell of a jolt," said passenger John Pierre of Edmonds, Wash., who was en route to Oakland.
Rita Schrank of Junction City, Ore., was asleep when the accident occurred.
"I felt a series of bumps," she said. "I felt like one, two, three, four and then it felt like it was going to go over."
Follmer said passengers were to be bused south to Redding to continue the trip on another Amtrak train.