Summer Sizzler- Denver 2026

The race.

The Summer Sizzler takes place August 8, 2026, in Thornton, Colorado, and offers race distances of 50 meters, 1 mile, 3.1 miles, 6.2 miles, and 15 kilometers. The 5K, 10K, and 15K distances include chip timing, custom bibs, designer shirts, and custom finisher medals. The 1-mile distance is untimed and provides the same shirt and medal. A kids' dash for ages 10 and under features an untimed format with youth-sized shirts and custom medals. Finishers receive complimentary shaved ice and treats. Free race photos are available, and participants can view live results. Youth pricing for the 5K and 10K is $17 for ages 12 and under. Registration deadline is midnight on Thursday, two weeks before race day, to guarantee a shirt size. A virtual race option is available. Team registration offers $5 refunds per person once four teammates register, with an additional $5 refund at ten registered team members.