Mountain Lakes 100
Olallie Lake, United States • 19 Sep 2026
Event overview
Mountain Lakes 100 is a trail ultramarathon held at Olallie Lake, Oregon, on September 19, 2026. The event distance is 100 miles and the field capacity is 150. The race is a Western States 100 qualifier.
Course and support
The route starts and finishes at Olallie Lake and runs along dozens of lakes, including about 60 miles on the Pacific Crest Trail. The course includes technical, rocky sections and multiple viewpoints of surrounding mountain peaks. Aid stations are described as well stocked and staffed by experienced volunteers.
Entry, requirements and policies
Registration opens January 1, 2026, at 7:00 AM PT and is not conducted by lottery. A wait list is used; in recent years organizers have cleared the wait list by early September. All entrants must complete 8 hours of trail work between October 1 of the previous year and September 1 of the race year; failure to submit required hours results in forfeiture of the entry. The organizer offers a cancellation credit equal to 50% of the race fee if cancellation occurs more than 30 days before the race; cancellations 30 days or less before the race receive no credit, refund, or transfer. The event is produced by Go Beyond Racing. Visit the organization's website for the most recent information.