Keys 100 Course Profile

Key Largo to Key West, FL, Florida

• Distance: 100 miles
• Elevation Gain: 100 ft
• Elevation Loss: 100 ft
• High Point: 18 ft
• Low Point: 0 ft
• Time Limit: 30 hours
• Month: May
• Finisher Rate: ~70%

A flat coastal 100-miler running from Key Largo to Key West through the Florida Keys along US-1. With virtually zero elevation gain, the challenge comes from relentless heat, humidity, wind exposure, and the mental grind of flat road running across 42 bridges.

Aid Stations

Name	Mile	Elevation	Crew Access	Drop Bag	Cutoff
Islamorada	20	5 ft	Yes	Yes	—
Marathon	45	8 ft	Yes	Yes	14:00
Big Pine Key	65	6 ft	Yes	Yes	20:00
Sugarloaf Key	82	5 ft	Yes	Yes	25:00
Stock Island	95	5 ft	Yes	No	28:00

Course Segments

Segment	Miles	Terrain	Difficulty	Notes
Key Largo to Islamorada	0–20	flat	moderate	Flat road running. Set your pace early.
Islamorada to Marathon	20–45	flat	moderate	Seven Mile Bridge section. Wind exposure.
Marathon to Big Pine Key	45–65	flat	hard	Heat builds through afternoon. Hydrate aggressively.
Big Pine Key to Key West	65–100	flat	hard	Final push through the night to Key West.

View the full interactive elevation profile, 3D course flyover, and race strategy tools on HARDN.