Roxborough Ultras

Roxborough Ultras is a late-summer trail ultramarathon in Roxborough State Park, Colorado, offering a 50K and 50M on fully marked, all-trail courses. Both distances feature sustained climbing, technical sections, exposed terrain, and long stretches with little flat relief.

The 50K includes over 4,180 feet of elevation gain.
The 50M includes over 8,450 feet of elevation gain.

The courses spend extended time on iconic Roxborough-area trails, including long out-and-back segments and sustained climbs with limited shade. This is a physically demanding race that develops over the course of the day, where pacing, fueling, and heat management are continuous considerations.

August conditions in Roxborough are typically hot and dry, and natural water sources are unreliable or dry at this time of year. Aid stations are intentionally spaced and fully stocked, but runners should expect longer gaps between support than at shorter Front Range events. All participants are required to carry a minimum of 20 oz of water at all times.

Roxborough Ultras is capped intentionally in its first year to prioritize quality, safety, and execution over volume. Pricing is flat, with no tiered increases, reflecting a focus on a well-run experience rather than upsells or late-entry premiums.

This race is designed to be exciting, hard, and well supported, while still respecting the terrain and the effort required to move through it.