After considerable investigation, Segment 4 of Air Mail Route 76 was canceled. Western Air Lines discontinued serving El Centro and Yuma on July 18, 1952 over Air Mail Route 13; and Bonanza Air Lines activated the extension of Air Mail Route 105 from Phoenix to Los Angeles on July 15, 1952. Ajo and Blythe, located between Yuma and Phoenix, were served on only one flight each way daily, and not on the same flight.

This cover was carried on the inaugural Air Mail Route 105 flight from Yuma, Arizona to Los Angeles, California and is listed in the Contract Air Mail Flights (CAM) Section of The American Air Mail Catalogue as 105W13.

The Civil Aeronautics Board and President Lyndon Johnson approved the simultaneous merger of three airlines for the first time in early 1968. Pacific Air Lines, Bonanza Airlines, and West Coast Airlines are combined to form Air West. Air West provided service to eight Western states, Canada, and Mexico within its 8,800-mile system.

Howard Hughes purchased control of Air West. After a number of lawsuits, he renamed the airline Hughes Air West on April 1, 1970.

Effective on October 1, 1980, Republic Airlines, Inc. purchased Hughes Airwest and made the carrier a wholly-owned subsidiary known as Republic Airlines West, Inc.

On January 23, 1986, Northwest Airlines announced the biggest merger in U.S. civil aviation history to that date — an $884 million purchase of Republic Airlines. The two carriers filed a merger application with the Department of Transportation on January 27. The Justice Department opposed the merger because it would “substantially lessen competition” in violation of antitrust laws. Full hearings regarding the merger were held and on July 31 the Department of Transportation approved Northwest Airlines’ takeover of Republic Airlines. On August 12 the acquisition of Republic was completed as officials from both airlines transferred ownership of Republic to Northwest. On October 1, 1986, the operations of Republic were fully integrated with a single Northwest flight schedule.

On April 15, 2008, Delta Air Lines and Northwest Airlines announced a merger agreement. The merger of the two carriers formed what was then the largest commercial airline in the world, with 786 aircraft. Delta Air Lines' brand survived, while Northwest's brand officially ended in 2009.