KEYS100 Ultramarathon

The KEYS100 Ultramarathon is an annual running event taking place across the scenic Florida Keys, specifically from May 17-18, 2025. This ultramarathon features multiple race options, including a 100-mile individual ultra, a 50-mile individual ultra, a 50-kilometer individual ultra, and team relays for both 100 and 50 miles. The course is primarily off-road, with about 75% of the race run on trails, offering participants a unique experience in a tropical paradise.

The event emphasizes safety and community, requiring runners to have support crews and adhere to specific race rules. Visit the organization's website for the most recent information.