Another step in the Civil Aeronautics Board's efforts to reduce traffic
at major hub airports was taken with Continental Air Lines inauguration of
service to Ontario, as a “Satellite Airport” co-terminal with Los Angeles. Service
was by nonstop flights to Ontario from both Chicago and Denver, with flights
continuing to Los Angeles beyond Ontario.
This cover was carried on the inaugural Air Mail Route 29 flight from Ontario, California to Chicago, Illinois (where it was backstamped) and is listed in the Contract Air Mail Flights (CAM) section of The American Air Mail Catalogue as 12E77.
Continental Airlines and United Airlines merged in an $8.5 billion all-stock merger of equals on October 1, 2010.