What happened
On October 6, 1955, a Douglas DC-6 operated by United Air Lines departed Denver, Colorado, bound for Salt Lake City, Utah. The flight was part of a multi-stop journey originating in New York. After experiencing weather-related delays during the previous legs of the trip, the aircraft took off at 06:33 with 6 and 63 passengers on board. At the time of departure, the aircraft's gross weight was 64,147 pounds, which was within the permitted limits, though a loading error had placed the rear baggage compartment 100 pounds over its specific maximum capacity.
Following takeoff, the flight made its final radio contact with the company. The aircraft failed to reach its scheduled reporting point at Rock Springs, Wyoming, at 08:11. After repeated unsuccessful attempts to reestablish communication, an emergency was declared, triggering a large-scale search operation involving the Wyoming Air National Guard, Civil Air Patrol, and United Air Lines.
The wreckage was located later that morning near Medicine Bow Peak, approximately 33 miles west of Laramie, Wyoming. The aircraft had struck a nearly vertical rock face on the eastern slope of the mountain at an elevation of 11,570 feet. The impact caused the plane to disintegrate, scattering debris across the mountainside and onto the slopes below. There were 66 fatalities in the accident.
Findings
Investigations into the crash determined that the aircraft struck the mountain at an altitude just 60 feet below the peak's summit. Evidence from the wreckage showed four distinct scars on the cliff face, created by the engines and propellers hitting the rock. The investigation found that the weather conditions along the intended flight path were favorable for flying at the planned 10,000-foot altitude.
The primary factor in the accident was the pilot's deviation from the assigned flight route. Observations indicated the aircraft was flying significantly west of its prescribed course and was seen moving in and out of cloud layers approximately 21 miles away from the intended path prior to the impact.