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Course Highlights
The Colfax Marathon is the ultimate urban tour of Denver, starting and finishing at Ferril Lake in City Park at 5,280 feet — Mile High elevation. The marathon course winds through Denver’s most iconic landmarks: runners pass through Empower Field at Mile High on the warning track (twice!), traverse a full mile inside Denver Zoo with elephants, giraffes, zebras, and lions as live spectators, high-five firefighters inside Denver Fire Station #1, and take in sweeping views of the Rocky Mountains from Sloan’s Lake in Lakewood. The 26.2-mile USATF-certified course is a Boston Marathon qualifier with approximately 700 feet of total ascent across the 5,180–5,480-foot elevation range.
Race Details
Race weekend spans three days in May. The 5K Kickoff fires off Saturday morning at City Park, while Sunday brings the main events: the Full Marathon starts at 6:00 AM, the Half Marathon (which includes the beloved Zoo Mile) at 6:30 AM, and the Urban 10 Miler at 7:00 AM from RMCAD in Lakewood. All Sunday races finish at City Park with a massive festival featuring live music, food trucks, and a beer garden lakeside. Every race bib includes a free RTD transit pass for the day. The marathon relay accommodates teams of five runners divided into four legs through Denver’s neighborhoods.
Why Runners Love It
The Colfax Marathon draws runners from all 50 states and dozens of countries. The Half Marathon regularly sells out months in advance, and the Zoo Mile — the only race in the country routed through a major zoo — is a bucket-list experience. The flat-to-rolling course suits first-timers and Boston-qualifier seekers alike. The post-race festival at City Park, with Avery Brewery craft beer and lakeside views, is considered one of the best finish-line parties in the Mountain West.
Race Weekend Tips
Denver sits at exactly 5,280 feet elevation, so if you’re traveling from sea level, arrive at least 2–3 days early to acclimate. The expo at Empower Field at Mile High on Friday and Saturday is mandatory for bib pickup — plan accordingly. Sunday road closures span 5 AM–1 PM across much of central Denver and Lakewood; carpooling or using the included RTD pass for your return trip is highly recommended. Race morning temperatures in mid-May typically range from the upper 30s to mid-50s°F, so layer up at the start.
Register
Registration for the 2027 Colfax Marathon opens in August 2026. Visit runcolfax.org for entry details, course maps, charity partner programs, and expo logistics.
Denver, Colorado United States
Course Highlights
The Colfax Marathon is the ultimate urban tour of Denver, starting and finishing at Ferril Lake in City Park at 5,280 feet — Mile High elevation. The marathon course winds through Denver’s most iconic landmarks: runners pass through Empower Field at Mile High on the warning track (twice!), traverse a full mile inside Denver Zoo with elephants, giraffes, zebras, and lions as live spectators, high-five firefighters inside Denver Fire Station #1, and take in sweeping views of the Rocky Mountains from Sloan’s Lake in Lakewood. The 26.2-mile USATF-certified course is a Boston Marathon qualifier with approximately 700 feet of total ascent across the 5,180–5,480-foot elevation range.
Race Details
Race weekend spans three days in May. The 5K Kickoff fires off Saturday morning at City Park, while Sunday brings the main events: the Full Marathon starts at 6:00 AM, the Half Marathon (which includes the beloved Zoo Mile) at 6:30 AM, and the Urban 10 Miler at 7:00 AM from RMCAD in Lakewood. All Sunday races finish at City Park with a massive festival featuring live music, food trucks, and a beer garden lakeside. Every race bib includes a free RTD transit pass for the day. The marathon relay accommodates teams of five runners divided into four legs through Denver’s neighborhoods.
Why Runners Love It
The Colfax Marathon draws runners from all 50 states and dozens of countries. The Half Marathon regularly sells out months in advance, and the Zoo Mile — the only race in the country routed through a major zoo — is a bucket-list experience. The flat-to-rolling course suits first-timers and Boston-qualifier seekers alike. The post-race festival at City Park, with Avery Brewery craft beer and lakeside views, is considered one of the best finish-line parties in the Mountain West.
Race Weekend Tips
Denver sits at exactly 5,280 feet elevation, so if you’re traveling from sea level, arrive at least 2–3 days early to acclimate. The expo at Empower Field at Mile High on Friday and Saturday is mandatory for bib pickup — plan accordingly. Sunday road closures span 5 AM–1 PM across much of central Denver and Lakewood; carpooling or using the included RTD pass for your return trip is highly recommended. Race morning temperatures in mid-May typically range from the upper 30s to mid-50s°F, so layer up at the start.
Register
Registration for the 2027 Colfax Marathon opens in August 2026. Visit runcolfax.org for entry details, course maps, charity partner programs, and expo logistics.