Get ready for an unforgettable running experience at the Blue Sky Trail Marathon & Half Marathon, taking place on the weekend of October 18-19, 2025, in the stunning landscapes of Fort Collins, Larimer. As the original and only trail marathon in Fort Collins, this event invites runners of all levels to embark on an exhilarating journey through the picturesque trails that connect Horsetooth Mountain Park and the Devil's Backbone Open Space.

Participants can choose between the challenging marathon, which features a significant elevation gain/loss of 3,500 feet, or the half marathon with a more manageable 1,800 feet of elevation. The course consists of 100% dirt trails, with a delightful 90% being Colorado's famous singletrack, ensuring a thrilling adventure for both seasoned trail runners and newcomers alike. With a generous nine-hour cut-off time, everyone has the opportunity to savor the breathtaking scenery ranging from smooth dirt trails to technical rock gardens. After crossing the finish line, celebrate your accomplishment with delicious barbecue and exciting sponsor giveaways. Don’t miss this chance to experience the beauty of Northern Colorado while challenging yourself in the great outdoors!