The airline was initially founded as Trans Sierra Airlines in 1970 by Chris Condon and Allan Silliphant with profits from their box office hit soft X and later R rated3-D filmThe Stewardesses. It was renamed Sierra Pacific Airlines when the FAA granted permission to operate aircraft weighing over 12,500 lbs. in 1971. Using Aspen Airways as an aspirational model, the original aircraft were one four-passenger, normally aspirated twin engine Piper Aztec, two eight-passenger turbo-charged twin engine Cessna 402s, followed by the 1973 post ski season introduction of a 44-passenger Convair 440 twin radial engine airliner. The aircraft were operated out of Hollywood Burbank Airport in southern California. Destinations served included Burbank, Las Vegas, Los Angeles, Fresno, Bishop, Mammoth Lakes and San Jose. In 1973, Sierra Pacific was purchased by Mammoth Mountain Ski Area. During the winter ski season of 1975-1976, the airline was flying nonstop service from Mammoth Lakes to Los Angeles, Las Vegas and Fresno with direct, one stop service to Burbank with 50 passenger seatConvair 580 turboprops and 19 passenger seat Handley Page Jetstream turboprops. The Mammoth Mountain Ski Area subsequently sold the airline. Sierra Pacific also flew de Havilland Canada DHC-6 Twin Otter aircraft as a scheduled intrastate State of California Public Utilities Commission airline while also having interstate CAB exemption to cross state lines. In February 1976 it became Mountain West Aviation. It is wholly owned by the Sierra Pacific Group. Until his death in November 2014, the long-time President of Sierra Pacific was Garfield Thorsrud, the founder of Mountain West Aviation. Thorsrud was a smokejumper early in his career and later served in the CIA, including with Intermountain Aviation.
Fleet
In January 2018, the Sierra Pacific Airlines fleet included:
According to its November 22, 1976, system timetable, Sierra Pacific was operating scheduled passenger service flown with Convair 580 and Handley Page Jetstream turboprop aircraft to the following destinations:
On March 13, 1974, a film crew for Wolper Productions filming a Bell Telephone Hour special about Ice AgeNeanderthal cavemen filmed at Mammoth Mountain Ski Area, was killed when a Convair 440 plane crashed into the nearby crest of the White Mountains during its climb out from Eastern Sierra Regional Airport in Bishop, California. All 36 on board were killed, including 31 Wolper crew and cast members, although David Wolper was not aboard the aircraft. The filmed segment was recovered in the tail section wreckage and was broadcast as the television documentaryPrimal Man., the NTSB has not been able to determine the cause of the crash. There were no indications of technical problems during takeoff, but no plausible explanation of pilot error could be given. It is one of only three uncleared NTSB cases.