City of Trees Marathon

Sunday, October 11, 2026 Course Maps will be updated once details have been finalized. GREAT SWAG and T-SHIRT DEADLINE Comfiest long sleeve t-shirt, swag thanks to our amazing sponsors, and finisher food/drink, all COT runners get a finisher's award. Please note that registrants registering after October 1, 2026 are not guaranteed a shirt. Please note courses utilize the Boise Greenbelt system. Should we run the Greenbelt, the river can be unpredictable. Systems and entities that govern the local Greenbelt are constantly dealing with these challenges. Typical issues are created due to sidewalk construction, sinkholes, flooding, etc. During the run, you may encounter wildlife that may cause a delay in your progress and/or change in your planned route. Or you may cause your own delay to stop and listen to the amazing sounds this course creates.