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Boulder Field 100

📅 September 11, 2027 (estimated date)📍 Jim Thorpe · United States

⚠️ 2027 edition: provisional information

The date is estimated from the 2026 edition (September 12, 2026), on the same day of the week. Courses, start times, fees and description are carried over from the previous edition: check them on the official website. This page will be updated as soon as the organizer publishes them.

Available distances

18 mi31.1 mi62.1 mi

About

Boulder Field 100 is a trail ultra organized by Uber Endurance Sports in Jim Thorpe, Pennsylvania, on September 12, 2026. Three formats are offered: a 100K (62 miles) starting at 5:00 AM, a 50K (31 miles) at 7:00 AM and an 18 Miler (29 km) at 7:30 AM. The name is a fair warning that rocks are part of the deal.

The 18 Miler is a good option for trail runners who want more than a half marathon without going full ultra, and the 50K is a classic first-ultra distance. The 100K is a serious step that rewards runners with a 50-mile finish already in hand. Whichever you pick, spend your build on technical trails to protect your ankles and your pace, add back-to-back long runs for the longer distances, and practice hiking the steep bits with purpose rather than forcing a run.

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