2025 Old Man Winter Bike Rally & Run

The 11th annual Old Man Winter Rally is a must-do Colorado endurance festival with mixed terrain adventures for all levels of riders and runners.

23 mile, 40 mile, and 75 bike courses include Boulder County's best gravel roads and the 75 mile course adds in canyons and snowy single track. Running courses include a 5K through Lyons and the scenic 10K can be combined with the 40 mile 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

All participants are supported with well-stocked aid stations, a hot meal, cold beer, and great winter swag!