2026 Detroit Free Press Marathon - Oct 18

International loop (two border crossings) marathon course in Detroit with 118m elevation gain. The headline is the border: the Detroit Free Press Marathon is the only U.S. marathon that crosses an international boundary, sending runners over the Ambassador Bridge into Windsor, Ontario, Canada around mile 3, then back to Detroit through the Detroit-Windsor Tunnel — the world's only official underwater international mile, the famous 'Underwater Mile' beneath the Detroit River. A valid passport or