The 10th annual Old Man Winter Rally is a must-do Colorado endurance festival with mixed terrain adventures for all levels of riders and runners. 50K or 100K bike courses include Boulder County’s best gravel roads and the 100K course adds in canyons and single track. Running courses include a 5K through Lyons and the scenic 10K can be combined with the 50K bike course for a wintry multi-sport challenge. All events come together for a big party with live bands, bonfires, hot food, cold beers, s’mores, and a huge expo. Reserve your spot before they’re gone at www.OldManWinterRally.com