In 1990, Mesa acquired Aspen Airways Denver hub and routes, except for Aspen's Denver to Aspen route. It attempted to acquire Aspen's codeshare with United. However United was unwilling to codeshare with an airline that only operated 19-seat turboprops. Mesa leased Embraer EMB 120 Brasilia aircraft from its former competitor in New Mexico, Air Midwest. With the Brasilias in hand, Mesa gained a codeshare with United for its Denver hub. Several Beech 1300 and Beech 1900 aircraft were repainted with the United Airlines scheme.