Thunder Valley Motocross Park

Thunder Valley Motocross Park in Morrison, Colorado is the premier motocross facility in the Mountain West and the home of the Thunder Valley National, one of the most distinctive rounds on the AMA Pro Motocross Championship calendar every June. Set in the foothills southwest of Denver against a backdrop of the Rocky Mountains, Thunder Valley sits at over a mile of elevation, which fundamentally changes how riders, bikes, and races behave. Bikes make less power at altitude, riders run out of oxygen faster, and late-spring Colorado weather can deliver everything from 95-degree heat to a freak hail storm in a single moto.

The track is a fast, flowing natural-terrain layout with significant elevation changes, hard-packed dirt that develops big square-edged ruts as the day goes on, and long straights that put a premium on horsepower a 450 just does not have at 5,500-plus feet. Riders coming from sea level should expect their lap times to drop by a couple of seconds and their forearms to be cooked sooner than they are used to. Local racers tune for thin air, run higher final-drive gearing, and pace themselves through the elevation gains on the back side of the property.

The Thunder Valley National regularly draws nearly 30,000 fans, making it one of the better-attended Pro Nationals on the calendar, and the spectator experience is among the best in the sport. Easy parking, real food vendors, a natural amphitheater feel from the rolling terrain, and the Denver skyline visible in the distance combine to give the weekend a destination-event feel. The June timing puts the race in the early heart of the Pro Motocross season, and Thunder Valley regularly produces the most dramatic title-shaping results of the early calendar.

Outside National weekend, the track is open year-round for local riders, with the dry continental climate keeping the dirt rideable deeper into the shoulder seasons than the wet Pacific Northwest tracks. Thunder Valley is the closest serious motocross training facility for racers across Colorado, Wyoming, New Mexico, western Nebraska, and western Kansas, and it draws a steady stream of out-of-state riders who fly into Denver to log altitude miles before nationals. The Front Range moto scene treats Thunder Valley as the regional anchor, and the practice schedule pulls families from across the I-25 corridor.

Access is straightforward. The track sits 30 minutes from downtown Denver and 45 minutes from Denver International Airport, an easy travel-day for fly-in riders and one of the more accessible Pro Nationals in the country. For anyone searching for motocross tracks in Colorado, MX tracks near Denver, or the bucket-list Mountain Time Zone Pro National venue, Thunder Valley is the answer with the highest elevation and the strongest pedigree.