On May 15, 1920, the third leg of the transcontinental route, Chicago, Illinois, to Omaha, Nebraska, via Iowa City, Iowa, was established, performing service similar to that performed on the routes between New York and Chicago. On August 16, 1920, a route was established between Chicago and St. Louis, and on December 1 of the same year a route was also established between Chicago and Minneapolis. Both of these latter routes expedited mail between the points named, and were feeder lines to mail trains and the transcontinental route at Chicago.
The last leg of the transcontinental route, Omaha, Nebraska, to San Francisco, California, via North Platte, Nebraska, Cheyenne, Rawlins and Rock Springs, Wyoming, Salt Lake City, Utah, and Elko and Reno, Nevada, was inaugurated on September 8, 1920. The initial westbound trip was made at the rate of 80 miles per hour and was flown without a forced landing, either for weather or mechanical trouble. The airplane carried 16,000 letters, which arrived in San Francisco 22 hours ahead of the best possible time by train.
Due to the necessity of economizing on expenditures, and the fact that Congress had not specifically authorized it, the New York-Washington route was discontinued on May 31, 1921, and the Minneapolis-Chicago and the Chicago-St. Louis routes on June 30, 1921. Operation was then confined to the service between New York and San Francisco, for which appropriation was specifically made.
The new routes would prove as dangerous as the old. D. B. Colyer, a chief of flyers, wrote to Edgerton DB Colyer, a chief of flyers, wrote to Edgerton that the Cheyenne-Salt Lake City route was "a good one to kill the men that you seem to have a grudge against or want to see out of the way."