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
- 184 m of climbing: rolling, not pancake-flat.
- Open registration — 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.
