Frontier Airlines is an airline that went bankrupt in the 1980s.
Frontier 737 in 1979
During the 1990s, Frontier Airlines was revived, using Boeing 737 jets. Just like the original Frontier, it flies out of Denver, Colorado. Unlike the old airline, it is out of Denver International Airport, and not Stapleton Airport. The planes used in the airline's re-incarnation are noted for colorful depictions of wildlife on the vertical rear fins of aircraft. The current Frontier has routes extending from coast to coast, with connections through Denver.