Race for the Refuge

SEP
27
2026
Trail races at the Assabet River National Wildlife Refuge in Sudbury MA include a 10K, a 30K and a 6 hour timed event. The course uses dirt and gravel double track trails with two aid stations and cupless fueling.
Sun 27 Sep 2026
10k Trail Race 30k Trail Race 6-Hour Trail Race

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Race for the Refuge

Race for the Refuge takes place at the Assabet River National Wildlife Refuge in Sudbury, MA. The course starts at the refuge visitor center and runs through ponds, pine and oak forest, and past former military bunkers. The double track trails are a mix of dirt and gravel.

Distances and events:

  • 10K Trail Race: one loop
  • 30K Trail Race: three loops
  • 6 hour Trail Race: timed event, multiple loops allowed

The 6 hour event ranks runners by total loops completed and elapsed time; a lap must be completed before the event end to count toward final mileage. Pacers are permitted only for the 6 hour race; pacers must register and check in to receive a pacer bib. One pacer at a time per runner, no muling, and pacers may use aid stations at no cost.

There will be two aid stations offering water, hydration mix, pretzels, orange slices, banana halves, Swedish fish, coke, and ginger ale. This is a cupless race; runners should carry and pack out their own fuel and waste. Dogs are not permitted on refuge lands and children must be supervised. Littering or leaving the marked course can result in disqualification.

Registration fees vary by event and are considered charitable donations used for refuge improvements and nature education. Prizes will be awarded to top male, female, and nonbinary finishers in each event. Visit the organization's website for the most recent information.

30 km
30k Trail Race
10 km
10k Trail Race
6-Hour Trail Race
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