At Colfax, we run a 42.2 km city loop through a fire station, Empower Field twice, Sloan's Lake, downtown, and seven miles beside water. The hills are manageable; the constant 1,600 m altitude is the quieter tax. Registration opens in August, with entry still estimated near $180. Partners can use transit and meet us repeatedly, then recover in City Park instead of chasing a point-to-point course.
Better info coming — we're still verifying 5 fields on this race.
Why we'd pick it
- The 190 m climbing estimate is useful for planning, not a verified pacing number.
- Open · Direct entry — no lottery to lose.
- A non-racing partner gets a real weekend here — 5/5.
- Race day usually sits 6.1–20.8°C, about 41% chance of rain.
The course
The marathon starts and finishes at Ferril Lake in City Park, crosses downtown, runs through Denver Fire Station 1 and Empower Field twice, then reaches Sloan's Lake and Lakewood before returning along river and bike paths. The profile is moderate, but every kilometer is near 1,600 m above sea level and the late climb back toward City Park arrives after 35 km.
Difficulty and PR scores
Difficulty is the course and the conditions. The PR score is a separate read on a fast clock. Missing inputs are dropped and the other weights are rescaled. The method, with the weights.
- Difficulty
- 55 / 100
- PR / BQ friendliness
- Not scored
Weight used: 60%. Need 40% before we print a number.
Weight used: 30%. Need 45% before we print a number.
Weather median for 2011–2025, race date ±7 days, 225 days, at Start / finish, City Park. Grid elevation 1604 m.
No cited BQ rate for this race.
| Input | 0–100 | What went in |
|---|---|---|
| G Gain | — | No trusted gain per km. Uncertain stored gain is not used. |
| A Altitude | 76.7 | 1604 m. 0 below 300 m, 100 at 2000 m. Source: open-meteo-grid. |
| H Heat | 75 | High 20.8°C, dew point 3°C. The hotter of the two bands is used. |
| W Wind | 15 | 2.5 m/s median. Bands: under 3 → 15, under 5 → 40, under 8 → 70, else 100. |
| S Surface | 15 | road. Road 15, mixed 45, gravel 70, trail 90. |
| T Cool temps | 25 | 100 minus heat (75). |
| B BQ evidence | — | No cited BQ rate. |
Stays around the race
These are area searches near the published start, finish, and course pins. TripRace may earn a commission if you book, at no extra cost to you. We are not naming a hotel.
- Start and finish — City Park start / finish
- Along the course · Downtown Denver — Downtown Denver
- Along the course · Empower Field — Empower Field
