Dizzy Horse Backyard Ultra

Event overview

Dizzy Horse is a winter backyard ultra held on December 12, 2025 in Idaho Falls, Idaho, hosted at the Bonneville County Exhibition Hall and Sandy Downs Park (7791 S 15th E). The format requires all remaining participants to run a 4.167-mile loop each hour until only one runner completes one more loop than the next finisher. Results are based on completed loops; non-winners receive a DNF award and milestone awards are given for benchmarks such as 50 miles (12 hours) and 100 miles (24 hours).

Course and rules

The marked loop mixes grass, horse racetrack, dirt, sand and pavement and is often snowy in December. The course surface breakdown is listed as roughly 25% grass, 20% racetrack, 35% dirt, 8% sand and 12% pavement. There is a short climb of about 35 feet in the sand section along the canal. Competitors must be in the starting corral at the top of each hour and start with the bell; no late starts are allowed. Water is available at the 2-mile mark. No personal aid is allowed on course, no artificial aids such as trekking poles, and slower runners must allow passes.

Logistics and services

Base registration is listed at $50. Paid upgrades and merchandise are offered, including a deluxe aid station, reserved 10'x10' indoor transition spaces (limited number), T-shirts and hoodies. The basic aid station provides water; the deluxe aid station offers a wider variety of food and beverages with access windows set by the organizers. Crew may provide aid only in the transition area after a lap is finished and have limited setup options. Visit the organization's website for the most recent information.