Jill Davis has been a skier since she was a child. She and her fiancé have skied on Epic and Ikon passes in recent years, but they’ve just about had it with increasingly crowded slopes and Interstate 70 traffic jams. That prompted them last month to try Bluebird Backcountry, a ski area without chairlifts near Rabbit Ears Pass that gives skiers and snowboarders a feel for the backcountry experience in a controlled environment. A ski area without lifts, after all, is a ski area without lift lines. “We heard about Bluebird, getting away from crowds, exploring new territory, so we signed up,” said Davis, 43, who lives in Littleton.