There are 4 marathons in Cornwall, Connecticut in 2026. The next is the Denali - 40 Mile + (40 Miler) - if you can only spare your whole weekend - Elevation Endurance Ultra Trail Marathon - 43 + Miles | 48 Hour - IronHike (Iron Hike) Fall (October / Oct) - Solo - Mohawk Mountain, Connecticut (CT) - Run, Hike or Walk with us as we redefine race day. on October 2.