Great Lakes Aviation, Ltd. is a regional airline operating as an independent carrier and as a code share partner with United Air Lines, Inc. (United Air Lines or United) and Frontier Airlines, Inc. (Frontier Airlines or Frontier). As of February 28, 2007, the Company served nine states with 28 destinations to and from Denver, Colorado, four destinations to and from Phoenix, Arizona and two destinations to and from Albuquerque, New Mexico.