Welcome to the Platte River Half Marathon, Relay & 5k race, one of the most exciting and popular races in the Denver Metro Area! This race is held annually in Littleton, CO. We’re thrilled to announce that registration for our upcoming 2027 event on Sunday, April 11th is open for the half-marathon and relay race. The race starts and finishes next to the beautiful Platte River Trail and adjacent to the popular Breckenridge Brewery campus. Join us for an epic post-race party at the Brewery with food, vendors, live music, and of course beer! 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 Salute Colorado. Thank you for your support, and we can’t wait to see you at the finish line! Questions? Visit our race website here. Entry fees are non-refundable and non-transferable. There are no deferrals to future years.

Typical conditions

For events around April 2027 in Littleton, CO, United States: Typical spring conditions in this region — mornings can still be cool; confirm start-time guidance on the official page.

How to prepare

Half marathon prep usually includes a weekly long run that builds toward 16–20 km, plus easy runs for recovery. Confirm packet pickup and start procedures on the official registration page.

Plan longer races for 2026