Boulderthon Marathon course

Photo: Triprace / OpenAI image generation · AI-generated editorial image

Running · Boulder, US

Boulderthon Marathon

September 27, 2026Marathon · Half marathon · 10K · 5K184 m

At Boulderthon, we get a downtown start, reservoir and foothill roads, about 184 m of gain, and a Pearl Street finish. The course is friendlier than Boulder's reputation suggests, but it still sits around 1,625 m and September can warm quickly after a cool start. Entry is currently estimated near $180. Partners get the easiest Colorado setup here: walkable food, hotels, and finish-line access without mountain-road logistics.

Better info coming — we're still verifying 4 fields on this race.

Why we'd pick it

  • The 184 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 7–24°C, about 15% chance of rain.

The course

The 2026 marathon starts downtown, uses Boulder's quieter reservoir and foothill roads, and returns for a Pearl Street finish. Organizers list 603 feet of gain, about 184 m, after a substantial course reduction. The altitude near 1,625 m still changes effort, especially when exposed rural miles meet a warm, dry afternoon.

Official race site ↗

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