Denver International Airport reports an 8-point-3 increase in passenger traffic for January.
The increase was partly because of the return of low-cost carrier Southwest Airlines.
Airport officials say 3-point-5 (m) million passengers came through D-I-A, up 300-thousand from the same time last year.
Dallas-based Southwest started its three city service in January. D-I-A says it attracted nearly 79-thousand travelers, about two-and-a-half percent of the market share.
Denver-based Frontier Airlines had a 16 percent increase.
Elk Grove Village, Illinois-based United Airlines and its low-fare unit, Ted -- of Denver -- reported an increase of almost four percent.
United remains the largest carrier at D-I-A with 57-point-4 percent of the market share. Frontier trails with 19-point-3 percent of the share.