Experience Denver’s Best Half-Marathon and Relay Race

Lace up for the oldest half-marathon and relay race in the Mile High City!

Countdown To Race Day | Sunday, April 13, 2025








Registration Is Open for the 2025

Platte River Half Marathon & Relay!

Welcome to the Platte River Half Marathon & Relay race, one of the most exciting and popular races in Denver, Colorado! This race is held annually in Littleton just outside of the Denver Metro area. We’re thrilled to announce that registration for our upcoming 2025 event on Sunday, April 13th is open for the half-marathon and relay race.

Whether you’re an experienced runner looking to set a new PR, a newcomer looking to tackle your first half-marathon, or a team of runners wanting to run an exciting relay race, join us for a day of adrenaline-pumping running, scenic views, and all-around fun. What’s more, we donate a portion of the proceeds to the Leukemia & Lymphoma Society. Thank you for your support, and we can’t wait to see you at the finish line!

Looking for another race? Register for our sister race — the Colorado Marathon in beautiful Fort Collins! Run a Full, Half, 10k, or 5k and experience a scenic race like no other.

Explore One of Denver’s Best Races

Join us on a unique journey along the Platte River Trail, as you bask in some of the best natural scenery Denver has to offer. This race begins and ends in the Reynold’s Landing trailhead parking lot near the famous Breckenridge Brewery in Littleton where you will celebrate your victory with food, live music, and beer at the post-race party.

With the morning sunbeams reflecting off the river and the cityscape in the distance, you’ll experience the best of both worlds as you race through Littleton, Englewood, Sheridan, and Denver. With a total ascent of 420 feet, this scenic out-and-back course is perfect for runners of all ages, levels, and abilities. So, whether you’re looking to beat your personal best or just enjoy a beautiful day out on the trail, the Platte River Half Marathon & Relay promises an unforgettable adventure!

One Day. Two Races.
Fun for Everyone. Let’s Go!

Half Marathon

Half the distance of a full marathon — all the glory! Join us on a thrilling 13.1-mile race along the stunning Platte River. It’s more than just a race, it’s an exciting adventure!

Relay Race

Want to run with friends? Join a relay team and enjoy this race with others! Perfect for families, couples, and co-workers! Every member of a three-person team receives a finisher’s medal!

Get Your Swag on With the Platte River Half Marathon & Relay!

Running the Platte River Half Marathon & Relay comes with more than just the satisfaction of completing a challenging race. All finishers also enjoy some awesome swag, like a long-sleeve tech-T, a finisher’s medal, a collapsable HydraPak speed cup, an e-goodie bag, and more! Register today to enjoy these exclusive race perks!

Celebrate at the Breckenridge Brewery Post-Race Beer Garden

After crossing the finish line, it’s time to celebrate your accomplishment with friends old and new! We’ve partnered with Breckenridge Brewery and Good Company Hard Seltzer to provide an awesome post-race party where you’ll enjoy live music, delicious food trucks, and Colorado craft beer. Take in the spring sunshine and bask in the glow of your accomplishment with your finisher’s medal around your neck and a cold beer in your hand. This family-friendly event is the perfect way to cap off an amazing race day, so join us and let the good times roll!

Join Us in Our Commitment to a Greener Future

The Platte River Half Marathon & Relay is committed to sustainable racing. That’s why we’ve gone completely digital with our registration process to reduce paper waste and promote sustainable practices. We’ve also partnered with HydraPak for a cupless racing experience to eliminate 2,000+ paper cups from our race to keep the Platte River clean and waste-free! Reusable and collapsible Hydrapak Speedcups will be given to all participants to clip, stash, or carry during the race and use at hydration stations. So join us in our efforts to run toward a greener future together! Thank you for helping us protect and maintain the natural beauty of the Platte River!

Become a Sponsor and Join Us in Making a Difference

We’re looking for sponsors to help support our race, and we’d love to have you on board! It’s not just about marketing — it’s about connecting with a dynamic and motivated community of active individuals and fitness enthusiasts. With more than 21 years of races under our belt, our event has gained immense popularity, attracting both beginners and experienced runners year after year.

From registration to race day, our thoughtful and tailored strategy ensures a personalized and enjoyable experience for all participants. As a sponsor, your support will play an invaluable role in making this happen. Not only will you enjoy increased visibility with our diverse and engaged audience, but you’ll also be contributing to the success of one of the most exciting and well-organized races in Colorado. Join us today and be a part of something truly extraordinary!

Our Sponsors

Interested in Sponsorship opportunities with the Platte River Half Marathon & Relay? Become a Sponsor