Few marathons hand you a passport moment. In Detroit you'll start downtown at 7 a.m., climb the Ambassador Bridge at sunrise as the Detroit River opens out beneath you, run through Windsor, Ontario, and come back to the United States through the Detroit-Windsor Tunnel, the only official underwater international mile in the world. After that the course is a mostly flat loop through neighborhoods like Woodbridge and Eastern Market, with roughly 388 feet of gain, finishing near Campus Martius. Bring a valid travel document; the organizers won't advise on eligibility, so check the requirements yourself well ahead of time. You'll need to clear the tunnel by 10 a.m. and finish within 6.5 hours of the Last Chance Pacer. The race sells out: 2024 filled by July and 2026 was sold out with a waitlist, so register in January when fees are lowest.
Mostly flat loop that starts on Fort Street downtown, climbs the Ambassador Bridge into Windsor, Ontario, returns through the Detroit-Windsor Tunnel, then winds through Woodbridge, Eastern Market and the Dequindre Cut to a finish near Campus Martius. Course map ↗
Closes 2026-09-08. 2026 pricing tiers began Jan 1, 2026 ($120 Jan 1-6, rising to $170 by Sept 8); 2027 opening date not announced. Online registration for international races (marathon, international half, relay) closed 11:59 p.m. Sept 8, 2026; Detroit-only races closed Oct 8, 2026. Registrations are capped and the 2026 marathon is sold out with a waitlist. Fees are non-refundable; registration insurance is offered. A valid travel document is required for the international events; the organizers do not advise on border eligibility. Register ↗
- The race began in 1978 after Free Press managing editor Neal Shine returned from the Falmouth Road Race wanting a world-class marathon for Detroit. ↗
- It is billed as the only international marathon in North America where runners cross into Canada over the Ambassador Bridge at sunrise and return through the Detroit-Windsor Tunnel. ↗
- The tunnel mile under the Detroit River is described as the only official underwater international mile in the world; the race sold out for the first time in 2024, filling by July. ↗
- Marathoners must finish within 6.5 hours of the Last Chance Pacer's start; the finish line closes at 2 p.m. ↗
- Find My Marathon lists 388 feet of gain, 397 feet of loss, 3,569 finishers in 2025 and a 3.4% Boston-qualifier rate. ↗
Checked 2026-10-13. Always confirm on the official site before booking travel.