Boulder Rez Half

Get ready to experience the stunning beauty of Boulder, Colorado, at the Boulder Rez Half on April 11, 2026. This popular event offers a Half Marathon (13.1M), 10K, and 5K, attracting runners from across the West to its phenomenal scenery and welcoming atmosphere. The course largely loops around the picturesque Boulder Reservoir, treating participants to iconic views of the Flatirons and the majestic Rocky Mountains. Runners can expect a mostly flat course with only about 200 feet of elevation gain, primarily on packed dirt trails and roads, with some single track and paved sections near the start and finish. The Half Marathon completes two scenic loops, ensuring ample opportunities for aid at well-stocked stations offering water and Gatorade.

The Boulder Rez Half is renowned for its excellent organization, glamorous finisher medals, and a vibrant post-race celebration complete with music, awards, and refreshments. Typical race day conditions in mid-April feature ideal running temperatures, with historical highs around 63°F and lows around 34°F, and a low chance of precipitation, making it perfect for chasing a new personal record. While the course is mostly open and exposed to the elements, the breathtaking vistas of the surrounding landscape provide constant motivation.

Starting and finishing in the Boulder Reservoir parking lot, this spectator-friendly race provides a memorable experience for both participants and supporters. Runners consistently praise the race for its beautiful setting, efficient organization, and the positive vibes that make it a local favorite. Whether you're aiming for a personal best on a fast course or simply want to soak in the Colorado scenery, the Boulder Rez Half offers an unforgettable race day.