KEYS100 Ultramarathon
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Event
KEYS100 Ultramarathon takes place across the islands of the Florida Keys on May 16-17, 2026. Races finish at Higgs Beach on the Atlantic Ocean in Key West. The event is a pavement race with approximately 75% of the route on paved bike paths or sidewalks and the remainder on the road shoulder facing traffic.
Distances offered
- 100 miles (point-to-point from Key Largo to Key West)
- 50 miles (Marathon to Key West)
- 50 kilometers (Big Pine Key to Key West)
- 100-mile team relay
- 50-mile team relay
Format, safety and rules
Individual runners must have a registered support crew or share one under strict conditions; teams may include up to six runners for the 100-mile relay and up to three for the 50-mile relay. There are no aid stations or water stops along the route; participants are expected to be self-sufficient and may re-stock at public locations along the course. Crews must meet runners only at approved meet-up locations and use a single registered support vehicle per runner or team.
Race management provides reflective vests at check-in. Nighttime requirements include visible blinking lights and 360-degree reflective garments when outside the vehicle. Pacers are permitted at specified points on each distance. Timing mats and interim cutoffs apply; overall time limits are 32 hours for the 100-mile distance, 20 hours for 50 miles, and 12 hours for 50 kilometers. Photography and video rules limit personal photographers to two people per team who must ride in the support vehicle and register; use of drones is prohibited. Non-participants are not allowed to drive the course. Visit the organization's website for the most recent information.
