By 1931 Elko became a stop on a transcontinental passenger flight between New York City and San Francisco. In a 1931 timetable United Airlines predecessor National Air Transport is shown flying New York City–Cleveland–Toledo–Chicago, connecting to Boeing Air Transport's flight to Iowa City–Des Moines–Omaha–Lincoln–North Platte–Cheyenne–Rock Springs–Salt Lake City–Elko, and on to Reno–Sacramento–Oakland. Scheduled time of this flight was 31 hours westbound and 28 hours eastbound. By 1933 Boeing and National Air Transport were flying as United Airlines. By 1953 eastbound flights serving Elko would terminate at Salt Lake City and in 1955 a stop was added at Ely, Nevada. United served Elko with Boeing 247, Douglas DC-3, Convair 340, and Douglas DC-6B piston powered aircraft. The DC-6Bs operating on the San Francisco to Salt Lake City route stopping in Reno, Elko, and Ely were United's last non-jet service in the U.S.