OSS/CIA 50 Mile Night Run

JUN
12-13
2027
Nighttime trail ultrarun at Prince William Forest Park offering 50 mile and 25 mile options, strict cutoffs, required lights and mandatory hydration.
12-13 Jun 2027
50 miles 26 miles 25 miles

Always double-check with the organizer's website! This page may contain affiliate links.

OSS/CIA 50 Mile Night Run

The OSS/CIA 50 Mile Night Run is an overnight trail event in Prince William Forest Park that follows trails once used for Office of Strategic Service training. The course uses the park's single track and some fire road, with several bridge and National Park Service road crossings. Runners will cover sections of the trail in darkness and in daylight on different parts of the route.

Distances:

  • 50 miles: two 25+ mile loops
  • 25 miles: one 25+ mile loop with a recorded finish

The event enforces time limits and cutoffs for safety: a strict first loop cutoff at 6.5 hours after the start and a maximum allowed time of 14.5 hours to complete the second lap; podium contenders may face a 13 hour cutoff. There is a specified Oak Ridge aid station cutoff of 11 hours 15 minutes on the second loop. Lights and carried hydration are required on course. Pacers are permitted for the second loop only. Crews are restricted to the Telegraph Road Pavilion area and must be in the park before nightfall. Parking/park admission is included in the race fee at $20 per car. Camping is available at Oak Ridge Camping Area for $30 per night.

Aid support includes eight stations overall, with fully stocked main stations at the start/finish and Oak Ridge, plus two smaller aid points where South Valley Trail and Burma Road cross Scenic Drive. Visit the organization's website for the most recent information.

50 mi
50 Miler
26 mi
Nightmare-Athon
25 mi
25 Mile Option

Events nearby

Trail competitions in Prince William Forest Park offering a runnable 25 km one loop and 50 km two loop course with aid stations and published cutoffs.
A 5k and 10k at Burke Lake Park on mostly paved trails, with a virtual option, chip timing, race shirts and medals, and proceeds supporting The Brain Foundation housing program.
Trail and paved 5 km and 10 km courses at Burke Lake Park with chip timing, medal and shirt, virtual option, water stations, and awards for overall and age categories.
Trail races at Hemlock Overlook in Clifton VA on November 15 2026, with 5.2 mile and 9.5 mile options on riverfront hiking trails and park facilities.
Add Event
Help us complete the calendar!
  • Distance is at least 5 km
  • Event has a website or Facebook page
Website
Optional: Please provide your e-mail address if we may contact you.
Report a change
We will only update the data if the information is also on the website.