United Airlines passengers wait in the boarding area for their flights at Denver International Airport in Denver, Colorado.Robert Alexander | Getty ImagesUnited Airlines’ latest ski destinations will be accessible by bus.The Chicago-based airline on March 11 will start offering three-times-a-day bus service from its Denver International Airport hub to Breckenridge, Colorado and four-times-a-day to Fort Collins on April 1. Checked bags — and skis — will be transferred directly to the bus, provided by Landline, which will depart from a gate at the airport. Landline says seating capacity will be limited because of the Covid-19 pandemic.Travelers can book tickets directly to those …