A witness reports that a twin-engine airplane sputtered before it crashed about 150 miles southwest of Oklahoma City.
Oklahoma Highway Patrol Trooper Betsy Randolph said the Beechcraft Baron crashed Saturday afternoon near Mangum in Greer County.
The dead were identified by authorities as the 53-year-old pilot, Stephen Scott of Mangum and two passengers: 45-year-old John Hall and 20-year-old Edi Ortega, both of Altus.
She said she didn't know where the flight began or was headed.
A Patrol statement early Sunday said firefighters used a tool to extricate the victims from the wreckage and all were pronounced dead on the scene.
The Federal Aviation Administration is investigating and no immediate cause was given for the crash.