Mount Desert Island Marathon
The Lowdown
The Mount Desert Island Marathon (MDI) is Maine's premier destination marathon, run each October on the weekend following Indigenous Peoples' Day along the rugged coastline of Mount Desert Island near Acadia National Park. The USATF-certified 26.2-mile course starts in downtown Bar Harbor, climbs over Champlain and Dorr Mountains in the opening miles, passes Somes Sound (the only fjord on the U.S. Atlantic coast), and finishes in the maritime village of Southwest Harbor, with the toughest hills concentrated in the final 10K. A companion Half-Marathon starts in Northeast Harbor, and a 3-Person Relay lets teams split the marathon course; all events share the Southwest Harbor finish and peak fall-foliage scenery. The race is a direct Boston Marathon qualifier, though its hilly terrain makes it a tougher BQ attempt than flat courses. Registration is capped and has closed early in past years, so organizers recommend signing up well ahead of the October 18, 2026 race day.
Race Day
Weather Forecast
Elevation
Terrain Profile
Challenging elevation
Participants
Field Size
Medium-sized race
Crowd Rating
Spectator Support
Crowd data unavailable
Boston Qualifier
This race is a certified Boston Marathon qualifying event. Achieve your qualifying standard here on a verified course.
Acadia National Park
Somes Sound (only fjord on the U.S. Atlantic coast)
Champlain and Dorr Mountains
Southwest Harbor finish
Other distances available during the event weekend:
Bar Harbor, Maine, USA
US
Eligibility
- No explicit published minimum age; awards age groups begin at "19 & under", suggesting younger participants run with guardian consent
Required Documents
- Photo ID required for in-person bib pickup (no video-chat proxy pickup permitted)
Entry Methods
- Online registration via runmdi.org / zippy-reg.com
Cancellation & Refund Policy
Entry fees and add-ons are non-refundable, including for weather, injury, or other unforeseen circumstances; limited deferral options may be available per the official FAQ
Course record and BQ reputation: certified to USATF standards and a direct Boston Marathon qualifier, but consistently described by runners and race media as one of the hillier BQ-eligible courses in the Northeast, with major climbs in miles 1-3 and 17-18 and again near mile 25.
2026 General Registration opened February 14, 2026 at noon ET; the event has closed registration early in prior years.
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Community
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