OSS/CIA 50 Mile Night Run
Triangle, United States • 13 Jun 2026
Event overview
The OSS/CIA 50 Mile Night Run takes place in Triangle, VA at the Telegraph Road Pavilion in Prince William Forest Park. The event offers the following distances:
- 50 miles
- 25 miles
- 10 miles
The 50 mile race uses a 25+ mile loop that is run twice to reach 50+ miles. A night marathon option was added beginning in 2023 and allows runners a specified time window to complete one loop. Registration closes Tue, Jun 9 at 11:59 PM ET.
Course and support
The course is primarily single track with some fire road sections and several bridge and National Park Service road crossings. Two fully stocked main aid stations are located at the start/finish (Telegraph Road Pavilion) and at the half-way point for each loop (Oak Ridge Camp Ground). Two additional mini-aid stations provide a smaller selection of food, water, and Tailwind where South Valley Trail intersects Scenic Drive and where Burma Road intersects Scenic Drive.
Rules and park information
Crews are allowed only at the Telegraph Road Pavilion start/finish. The National Park Service requests that crews remain at their location in the park for safety reasons. Pacers are permitted beginning at the second loop from Telegraph Road Pavilion. Prince William Forest Park was established in 1936, contains about 37 miles of trails on more than 15,000 acres, and is the largest protected natural area in the Washington, D.C. metropolitan region. Visit the organization's website for the most recent information.