It's a little late to start training, but if you're a long distance trail runner, you're probably already planning to take part in Saturday's Aspen Backcountry Marathon. Runners will attack the 26.2-mile trail run that includes 4,000 vertical feet of climb over the course of the race. To get a jump on the expected warm temperatures, the race begins at 6 am in Koch Lumber Park in Aspen. The race course will include a climb up Smuggler Mountain and into the Hunter Creek Valley, as well as portions of the Sunnyside Trail, Buttermilk, Little Cloud Trail and the Ajax Trail on the way to the finish line. Details at www.aspenbackcountrymarathon.com.