What are you going to be for Halloween? How about haggard and cooked and loving every minute of it? Check out this doozy in Colorado’s San Luis Valley: the 12 Hours of Penitence Mountain Bike Race.

This 12 hour mountain bike endurance event is becoming a creepy classic. Rip this eerie and cool 16-mile course through the rugged volcanic canyons as they meander through conifer and open to arid desert zones.

The area is a gem of recreation in the San Luis Valley, lined by the San Juan Mountains to the west and the Sangre de Cristo Mountains to the east. Hikers, wildlife viewers, history buffs, trail runners and mountain bikers enjoy the area. Climbers flock to the walls of volcanic rock (check out our sweet video on climbing in the canyon) .

This year’s race is on Friday the 13th (see, creepy) and they do offer on-site registration at Penitente Canyon on Friday before the race.

For more information visit 12 Hours of Penitence.