In 1925, the Post Office began to make contracts with private operators to carry air mail. One route, from Pasco, Washington, to Elko, Nevada, called CAM 5 (Contract Air Mail route number 5), was awarded to Walter T. Varney. Varney acquired six new Swallows for the dangerous route over the mountains and desert. On April 6, 1926, 2,500 residents of Pasco came to see pilot Leon Cuddeback and the first mail-laden Swallow take off for Elko via Boise, Idaho. Varney found that the Swallows were underpowered and larger Wright J-4 engines were installed quickly thereafter. Later, Varney Air Lines and other companies, including Boeing Air Transport, merged to become United Air Lines.
The Museum's example is a 1928 Swallow Commercial or "OX-5 Swallow" restored to look like a Varney Swallow Mail Plane. The plane was originally powered by a Curtiss OX-5, 90-horsepower engine but currently has a Continental W 670 6N 220-horsepower power plant. In 1976, it was flown by Buck Hilbert for United Airlines' fiftieth anniversary.