Ranger Led Snowshoe Walk NPS photo. Our popular ranger-guided snowshoe walks are a great way to explore snowy trails. Snowshoe programs are usually offered from December - March, as long as there is at least 8 inches of snow on the ground. Walks are added to our online program calendar as soon as snow is deep enough. Visitor centers also post snowshoe walk schedules on bulletin boards. Check program announcements for details on how to make reservations to hold your spot.