Two people died Monday morning when the aircraft they were in crashed on Sherwin Grade in eastern California about 20 miles south of Mammoth Lakes.
The plane was heard sputtering and seen spiraling toward the ground by a witness who reported the crash at 11:29 a.m. The victims' identities have not been released.
Officials with the Mono County Sheriff's Department say it is thought the small plane was on a flight plan from the Riverside, Calif., area heading north toward Mammoth Lakes.
The summit of Sherwin Grade is between Bishop and Mammoth Lakes on Highway 395 at an elevation of about 7,000 feet.
Deputies from the sheriff's department, California Highway Patrol, Mammoth Lakes Police Department, miscellaneous fire agencies and other rescue vehicles responded to the top of the grade, where rescuers located the crash site.
The National Transportation Safety Board will be traveling to the crash site today to start an investigation to determine the cause of the crash.
