7 Best Marathons in Colorado | 2024-2025

From Denver to Fort Collins to Manitou Springs to Aspen to Colorado Springs, and more.

Colorado is a runner’s paradise, boasting some of the most scenic and challenging marathon courses in the country. Whether you’re a seasoned endurance athlete or new to the sport, the Centennial State offers an incredible lineup of marathons that will test your limits and leave you in awe of the stunning natural beauty.

In this comprehensive guide, we’ll take you through the 7 best marathons to add to your 2025 race calendar, covering everything from the iconic Pikes Peak Ascent to the fast and flat Denver Colfax Marathon. Get ready to lace up your shoes and conquer the altitude as we explore the top running events that Colorado has to offer!

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What are the Best Marathons in Colorado?

Here are the best marathons in Colorado:

Denver Colfax Marathon

Denver | May 18, 2025

Course Type: Rolling Hills

Elevation Gain: 693 feet (211m)

Participants: 25,000

Price: $124-$169

One of the largest marathons in Colorado, the Denver Colfax Marathon, the course takes participants on a fast, flat tour through the heart of Denver, showcasing the city’s iconic landmarks like the State Capitol building, Denver Zoo, and the scenic City Park. As a Boston Marathon qualifying event, the Denver Colfax offers runners a chance to secure their spot at the historic race while taking in the vibrant atmosphere of Colorado’s capital. The finish line festival in City Park is celebrated for its lively crowds, live music, and local food and beverage offerings.

Colorado Marathon

Fort Collins | May 4, 2025

Course Type: Downhill

Elevation Gain: 243 feet (74m)

Participants: 1,700

Price: $120-$200

For those seeking a more serene and scenic marathon experience, the Colorado Marathon is a must-add to your racing calendar. This point-to-point course follows the Poudre River Canyon, offering stunning mountain and river views throughout the 26.2-mile journey. The net elevation drop of over 2,000 feet makes the course relatively fast, but the challenging climbs interspersed throughout the route ensure runners will be tested. The rewarding experience of conquering this scenic route through the heart of Northern Colorado makes the Colorado Marathon a favorite among local and visiting athletes alike.

Pikes Peak Marathon

Manitou Springs | Sep 21, 2025

Course Type: Very Hilly

Participants: 616

Price: $190

The Pikes Peak Marathon and Ascent is a true bucket list event for serious trail runners and mountain enthusiasts. Offering two races in one – a marathon up and down Pikes Peak or just the Ascent – this grueling course gains an astounding 7,815 feet of elevation over 13.3 miles. Runners start at an elevation of 6,300 feet and push their limits to the 14,115-foot summit of Pikes Peak, taking in breathtaking vistas of the Rocky Mountains along the way. The descending portion of the course is just as challenging, testing the quads and mental fortitude of even the most experienced ultrarunners.

Aspen Valley Marathon

Aspen | Jul 13, 2024

Course Type: Downhill

Elevation Gain: 305 feet (92m)

Participants: 244

Price: $185-$235

Nestled in the heart of the Roaring Fork Valley, the Aspen Valley Marathon offers a picturesque course winding through the charming town of Aspen and the surrounding alpine scenery. The relatively flat and fast route makes this marathon a great option for Boston qualifiers, while the stunning views of the iconic Maroon Bells mountains provide ample motivation to push through the final miles. Runners can enjoy the vibrant post-race festival in downtown Aspen, complete with live music, local food and drinks, and a celebratory atmosphere that captures the essence of this outdoor-loving community.

Colorado Springs Marathon

Colorado Springs | Oct 4, 2025

Course Type: Hilly

Elevation Gain: 805 feet (245m)

Participants: 1,500

Price: $81.66 plus a $6.66 fee

For those seeking a fast and flat marathon in a stunning natural setting, the Colorado Springs Marathon is an excellent choice. The course winds through the beautiful Garden of the Gods park, offering breathtaking views of Pikes Peak and the Front Range mountains. Ideal for first-time marathoners or those chasing a personal record, the Colorado Springs Marathon features a net elevation drop of 300 feet, allowing runners to maintain a consistent pace. The finish line festival in Memorial Park provides a lively conclusion to the race, with live music, local food and beverages, and a celebratory atmosphere that embodies the active Colorado Springs community.

Boulderthon

Boulder | Sep 28, 2025

Course Type: Hilly

Elevation Gain: 1137 feet (346m)

Participants: 10,000

Price: $135–$259

The Boulderthon is a unique multi-race format that includes a full marathon, half marathon, and 10K. Held in the heart of Boulder, known for its active lifestyle and vibrant community, this challenging course features significant elevation gain and stunning mountain vistas. Runners will ascend a total of 1,600 feet over the 26.2-mile marathon route, testing their strength and endurance against the backdrop of the Flatirons and the iconic peaks of the Front Range. Whether you’re looking to tackle the full marathon or try your hand at a shorter distance, the Boulderthon offers a great opportunity to combine your love of running with the Boulder experience.

Steamboat Marathon

Steamboat Springs | Jun 1, 2025

Course Type: Downhill

Elevation Gain: 736 feet (224m)

Participants: 500

Price: $115-$160

Nestled in the Yampa Valley, the Steamboat Marathon & Half Marathon offers a scenic course with views of the Steamboat Ski Resort. The relatively flat and fast route, with a net elevation drop of 500 feet, makes this event a good option for those chasing a personal record. Runners will wind through the picturesque town of Steamboat Springs, taking in the charming Victorian-style buildings and the stunning mountain backdrop. With a smaller, more intimate atmosphere and a laid-back, community-driven vibe, the Steamboat Marathon & Half Marathon provides a charming and enjoyable running experience in the heart of this picturesque Colorado town.

Other Colorado Running Events

In addition to the top marathons highlighted in this guide, Colorado is home to a diverse array of running events throughout the year. From high-altitude trail ultramarathons to community 5Ks in scenic mountain towns, the state offers a calendar packed with opportunities for runners of all levels to challenge themselves and soak in the stunning natural beauty. Whether you’re seeking a rugged adventure, a fast and flat PR, or a lively community event, Colorado’s running event lineup has something to suit every runner’s needs and preferences.

Conclusion

Colorado is a runner’s paradise, offering a diverse array of marathons that cater to every skill level and running style. From the iconic Pikes Peak Ascent to the fast and flat Denver Colfax Marathon, this list of the 7 best marathons in the state will help you plan an unforgettable 2024 racing season. Whether you’re aiming for a Boston qualifier, seeking a scenic trail adventure, or simply want to experience the vibrant running culture of Colorado, these top-notch events have something for everyone. So lace up your shoes, train hard, and get ready to conquer the altitude and stunning natural beauty of the Centennial State!

Row Brown

Row Brown is the founder of Refresh Row. He is a keen marathon runner, his favorite being the London Marathon. He’s now set himself the mission of Running the Entire Length of Spain, which is scheduled for late 2024.