F^3 Cap Sauers Trail Marathon & 10 Mile 2027

The F^3 Cap Sauers Trail Marathon & 10 Mile runs take place within Cap Sauers Holding Nature Preserve, which is the largest undeveloped area in Cook County, Illinois. Packet pickup on race day begins at 6:30 a.m.; pre-assigned packets will be available for runners before they start on the trails. The event features a full 26.2-mile trail marathon and a precisely measured 10-mile race, both utilizing the preserve’s wide horse trails. The marathon crosses all maintained trails in the preserve and incorporates the Sag Valley Trail system, including the Yellow, Green, Blue, and Tan trails. The complete course includes over 1,000 feet of elevation gain, considered mountain-style running by Chicago area standards. Marathon participants begin with two circuits of the 10-mile course, followed by a direct out-and-back segment to the Will-Cook Road aid station. Aid stations are positioned frequently for a trail race, offering support at miles 3, 5, 8, 10, 13, 15, 18, 20, and 23. All participants receive a technical trucker hat, marathon finishers are awarded a finisher’s shirt, and all finishers get a wooden medal. Those who register early may also receive a personalized bib and select a lucky number if available.