Runners' Almanac
All marathons

Mid-May · Mountain West · Point-to-Point

Colfax Marathon

Denver, CO · Sunday, May 16, 2027

Named for Denver's Colfax Avenue and run at true mile-high altitude, the course passes through Mile High Stadium and the Denver Zoo. The altitude alone changes the math for most runners not acclimated to it, regardless of the flat-to-rolling profile.

Runs through Mile High Stadium & Denver Zoo

  • First Marathon
Official site

Opens the race organizer's website

Typical start

55°

Cooler than 17% of U.S. marathons

Modeled historical conditions

Elevation gain

400ft

Flatter than 38% of races

Estimated total climb

Field size

2.5K

Larger than 79% of races

Estimated field

PR potential

6.9/10

Ahead of 23% of races

Almanac model

Percentiles compare this race against all 224 U.S. marathons in the Almanac.

Course profile

400 ft gain · 0 ft net

Flat to rolling course, point-to-point.

0510152026.2
Schematic profile drawn from total gain, total loss and course category, on a shared vertical scale of 200 ft. Not a surveyed GPS trace.

Race-day weather

Modeled from location, month and coastal proximity, not verified race history.

6 AM

47°

Start

55°

Midday

65°

ExcellentGoodWarmHeat risk

Typical start sits at 55°F, good conditions.

Typical dew point 33°F, 6% chance of precipitation, wind around 10 mph. All modeled.

The bottom line

A quietly fast race that does not ask for much beyond honest pacing.

Colfax Marathon is a strong choice for a PR attempt, and Denver offers very little meaningful elevation. The tradeoff is that nothing about it is extreme in either direction.

Why runners choose this race

A point-to-point course around Denver, CO, with gentle rollers but no sustained climbing.

The case for it

  • First-time marathoners

The tradeoffs

  • You have not trained at altitude

Course and logistics

Course type
Point-to-Point
Surface
Road
Profile
Flat to rolling
Total gain
400 ft(estimated)
Total loss
400 ft(estimated)
Net elevation
0 ft(estimated)
Field size
~2,500 runners(estimated)
Crowd support
Pockets of spectators
Entry
Data coming soon
Start / finish
Start and finish in different locations

Race details

Typical timing
Mid-May
Next confirmed date
Sunday, May 16, 2027
Region
Mountain West
Editorial tier
Featured
Data last reviewed
2026-08-26
  • First Marathon
  • Point-to-point
  • Destination race

Similar races

Races with a comparable profile.

Mid-September · Mountain West

Malad Valley Marathon

Malad City, ID

Weather
56°Ftypical startModelled estimate
Field size
~300 runners
Course
Rolling
Elevation
400 ft gain · 0 ft net

Event listed as: Marathon

PR7Weather8Experience6