Waldo 100K
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Event
The Waldo 100K Ultramarathon is scheduled for August 1, 2026 in Oakridge, Oregon. The race is a loop-type course based at Willamette Pass Ski Area, located at elevation 5,120 feet and about 70 miles east of Eugene. The event distance is 100K.
Course
The route climbs several mountains, including Fuji, The Twins, and Maiden Peak, and returns to the ski area. The course is mostly single-track trails with some fairly remote sections. The route offers views of Waldo Lake. The organizer states the race is not a beginner-level ultra and recommends prior ultrarunning experience.
Registration and sustainability
Registration is handled by a lottery process that opens January 1, 2026; the previous lottery was held January 22, 2025 and results were published. The event participates in the Trail to Zero program. During lottery registration, participants may opt to contribute one dollar or more to a carbon offset program intended to address event-related travel emissions. The organizer cites a statistic from 29 events showing that most of an event's carbon footprint came from participant travel. Visit the organization's website for the most recent information.