The starting line at Copper. Photo by Sydney FoxI'm at the start line of the Copper en Fuego bike race surrounded by 161 other racers, my breath frosty in the night air. I'm not thinking about winning. I'm thinking: How I am going to stay on my bike on snow? Fireworks explode on the side of the course and we're off with a bang.

It's the first event of the Leadville Winter Mountain Bike race series, held at Colorado's Copper Mountain. The series of four races (three are at night) is considered the ultimate in winter bike racing—in the mountains anyway. The central Colorado high country offers snowy winters, mountain bike enthusiasts, and unrivaled elevation. The races average 12 miles, with courses covering groomed Nordic and alpine trails, roads, village plazas, and even stairs.

The Copper en Fuego start line is at the base of the American Eagle lift, right at the main plaza. Snow firmly packed from thousands of skiers and groomers soon turns to loose, six-inch deep chowder. Before we reach the deepest of it, we cross a four-foot patch of ice that riders try to run across. I slide out, trying to avoid a downed bike, and take another bike to the back of the head. I recover, pedaling towards the steepest hill of the race. On the down, my back tire begins to wash out, but I let off the back brake and feel like I'm riding deep sand. I'm feeling proud for not falling when the rider in front of me falters. My options? Bike directly over him or fall. We both go down. "That's way easier than crashing on dirt!" he yells.

I make my way to the Nordic trails and run the next few miles. The trails were groomed for the first time today and aren't yet packed down. I keep jumping back on my bike, only to fishtail three pedal strokes later. Finally, I spot a sidewalk ahead of me. The course winds back to the ski runs, and I feel a slight slip with every pedal stroke. I make it back through the plaza, choosing to end my race there and focus on rewarming my fingers. Standing at the finish line watching racers pass on their second lap, I make the most of a bonfire, the football game streaming live, and plenty of Dale's Pale Ale to go around.  —Sydney Fox

For more information about the Leadville Winter Mountain Bike series, visit cloudcitywheelers.com. The Winter Teva Mountain Games will host an On-Snow Crit for both Fat Tire (four-inch wide) and standard MTB tire categories this weekend. Find out more here.