Southwest Airlines has added six destinations from Denver, where the airline launched service in January 2006.
By May 2010, the airline will operate 127 daily nonstops from the Mile High City.
Starting March 14, Southwest will operate one daily flight between Denver and Hartford, Conn.; Boise, Idaho; Ontario, Calif.; Detroit; and Washington Dulles.
Also on March 14, Southwest will add a flight between Denver and Oklahoma City, for a total of three daily. The flights launching March 14 went on sale Thursday.
In May, Southwest will launch a Saturday-only flight between Denver and New York LaGuardia. Tickets for this flight will be available for sale in December.
Also in May, Southwest will add a daily flight on six existing routes from Denver: Tulsa, Okla.; New Orleans; Portland, Ore.; Oakland, Calif.; Baltimore/Washington; and Seattle.
"We have consistently invested flights and resources to support our growing Denver operation, and we'll continue to do so," said Southwest CEO Gary Kelly. "Denver has been a great success story for Southwest. As a result, we've been able to grow at a record pace."