Flight Details
The pilot and two passengers were returning to Twin Falls, Idaho, from Billings, Montana. Prior to departure, the pilot received two weather briefings. The intended route of flight required traversing high mountain terrain.
Weather Conditions
The weather forecast indicated low clouds, snow, turbulence, and icing conditions along the intended route. The Flight Service Station had forecast that the mountains would be obscured by clouds, and that the weather would include snow and turbulence. During the flight, the pilot radioed that he was encountering clouds near the mountains.
Accident Site
The accident site elevation was 10,000 feet. There was no evidence of a mechanical malfunction or failure of the aircraft structure, flight controls, engine, or propeller.
Investigation
The investigation noted the forecast adverse weather and the pilot's report of cloud encounter. No probable cause was explicitly stated in the source.