Marathon

Boulder Rez Marathon

Boulder Rez Marathon circles reservoir-side dirt and trail with broad Flatirons views, offering a largely flat Colorado full with about 200 feet of gain.

Next raceSaturday, August 15, 2026
Distance categoryMarathon
LocationBoulder, Colorado

Every link above goes to the race, its timing provider, or an official registration partner. Last checked August 4, 2026.

No live-tracking link for this edition yet. We add it as soon as the race publishes one.

Quick facts

  • Reservoir-side dirt and trail
  • Approximately 200 feet of gain
  • Flatirons views
  • Open, exposed Colorado course
Race-day forecast

Boulder Rez Marathon Race-Day Forecast

Drizzle on race day · 64-85°F (18-29°C) · 69% rain · 10 mph wind

Race-day forecast for Saturday, August 15, 2026 in Boulder, Colorado, US. Checked 4:14 PM MDT race-local time. Data: Open-Meteo.

About the Boulder Rez Marathon

Boulder Reservoir hosts this open-air marathon as the longest race in a multi-distance Saturday program. The Rez branding reflects the venue and distinguishes the event from Boulder's road races.

Course

The marathon uses mostly flat dirt and trail around Boulder Reservoir, with roughly 200 feet of total climbing. Repeated open stretches favor steady pacing but leave runners exposed to sun and wind.

Race-day weather

August mornings in Boulder may begin mild and become hot quickly under high-altitude sun. Reservoir wind and afternoon storms are possible, so early hydration and sun protection matter.

Past Boulder Rez Marathon dates and results

YearDateStatusResults
2026Saturday, August 15, 2026Upcoming

Boulder Rez Marathon FAQ

When is the Boulder Rez Marathon?

The 2026 Boulder Rez Marathon is on Saturday, August 15, 2026.

Does the Boulder Rez Marathon have live tracking?

Marathon Scout does not list an official live-tracking link for the 2026 Boulder Rez Marathon yet. We only add a tracker after the race or its timing provider publishes it.

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