Alaska Airlines will begin seasonal service from Seattle to Steamboat Springs, Colorado, on 18 December.
SkyWest Airlines will operate the twice-weekly flights with 70-seat Bombardier CRJ700s until 29 March 2014.
The announcement comes a little more than three weeks since Seattle-based Alaska announced new service between Seattle and both Colorado Springs and Omaha from 1 November and 7 November, respectively. Both routes will also be flown by SkyWest on CRJ700s.
No other airlines fly between Seattle and Steamboat Springs, Innovata schedules show.