Best Marathons in Colorado: Pikes Peak, Colfax & Fort Collins (2026)
Colorado's marathons span two very different challenges: altitude and elevation gain. The Pikes Peak Marathon climbs 7,815 feet to a 14,115-foot summit and back — the oldest continually held marathon in the country — while Denver's Colfax Marathon and the net-downhill Colorado Marathon in Fort Collins offer city-elevation racing where thin air, not terrain, is the main adjustment. Below, find the full Colorado marathon calendar, plus a closer look at all three signature races.
upcoming marathons in Colorado
Flagship Colorado Races
Pikes Peak Marathon + Ascent
Founded in 1956, the Pikes Peak Marathon is the oldest continually held marathon in the United States, running from Manitou Springs to the 14,115-foot summit of Pikes Peak and back down, climbing about 7,800 vertical feet up the historic Barr Trail. It was also the site of the country's first official women's marathon finish, by Arlene Pieper in 1959. The companion Ascent — a one-way, summit-only race — split off as its own event in the 1980s due to its popularity.
Colfax Marathon (Denver)
The Colfax Marathon is the largest marathon weekend in the Rocky Mountain region, drawing 25,000 runners in 2024 across a full weekend of races. The course starts and finishes in City Park, running through Denver Fire Station #1, along Sloan's Lake, and twice through Empower Field at Mile High — a rare chance to run onto an NFL field mid-race.
The Colorado Marathon (Fort Collins)
Held annually since 2002, the Colorado Marathon markets itself as "America's Most Scenic Course," running a net downhill from roughly 6,000 feet in the Poudre Canyon to 5,003 feet in Fort Collins. It's one of the most reliable Boston qualifiers in the state, with 16-18% of finishers qualifying most years.
