KEYS100 Ultramarathon
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KEYS100 Ultramarathon (May 16-17, 2026)
KEYS100 is a point-to-point ultramarathon across the Florida Keys, running from Key Largo to Key West and finishing at Higgs Beach in Key West. The 2026 event includes these race options:
- 100 miles (individual and team relay)
- 50 miles (individual and team relay)
- 50 kilometers (individual)
The race is primarily on pavement, with about 75% on paved bike paths or sidewalks and the remainder on the road shoulder facing traffic.
Race format, support and rules
Individual runners must use a support crew; two runners may share one crew only if they run together and meet crew-sharing limits. There are no aid stations or water stops along the route; runners and teams are expected to be self-sufficient with crew vehicle support. Each team or individual is allowed only one support vehicle; vehicle size, insurance and marking requirements apply and vehicles are subject to inspection. Photographers must register and ride in the support vehicle; drones are prohibited.
Timing mats and interim cutoffs are enforced. Time limits are 32 hours for 100-mile entrants, 20 hours for 50-mile entrants and 12 hours for 50-kilometer entrants; missing interim cutoffs or the overall time limit results in a DNF. Safety gear, reflective garments and lighting are required for night hours. Certain medical devices (IVs, supplemental oxygen) are prohibited and serious rule infractions can lead to penalties or disqualification. Visit the organization's website for the most recent information.