Mountain Lakes 100

Event overview

Mountain Lakes 100 is a 100-mile trail race held at Olallie Lake Resort in Oregon. The event is scheduled for September 19-20, 2026 and has a 30-hour time limit. The course runs between Mt. Jefferson and Mt. Hood and includes approximately 60 miles on the Pacific Crest Trail. Total ascent and descent is 11,700 feet. The field is limited to 150 entrants.

Course and logistics

The route includes technical and rocky trail sections, single-track running, and many views of mountain peaks and lakes. The course low point is about 3,300 feet and the high point is about 5,700 feet. There is very limited cell or internet service along the course, so live tracking at aid stations is not available; organizers use paper tracking and HAM radio for race operations. Runners may encounter horses on multi-use trails.

Registration, requirements and awards

Registration opens January 1 and closes August 31. Entry fees vary by date: $355, $370, and $390 tiers are listed. Capacity is 150. There are no transfers and no refunds; cancellations more than 30 days before the race receive a 50% credit toward a future race, and cancellations 30 days or less receive no credit. All entrants and waitlisters must complete eight hours of trail work after October 1 and by September 1 to keep their spot. Top finishers receive prizes; all finishers receive a belt buckle and a finisher pint glass, with a special buckle for finishes under 24 hours. Visit the organization's website for the most recent information.