Nordic trails are a popular winter alternative to skiing. This low-impact cardio workout is a great way to see the mountain and get some fresh air while making fresh tracks in the backcountry or on a groomed trail. Equipment rental is available at the many full-service cross-country centers scattered throughout the state. Daily trail passes and season passes are available and some resorts even host all-inclusive overnight trips, cross-country clinics and races. Check out our top recommendations for cross-country skiing in Colorado.