Cobscook Backyard Ultra

APR
26
2026
Experience a modified backyard ultra at Cobscook Bay State Park with 50k and 50 mile options for solo runners or relay teams. Run repetitive loops on vehicle free gravel roads in a scenic coastal forest setting.
Sun 26 Apr 2026
2/3 Person Backyard Relay... Solo Backyard 50k 2/3 Person Backyard 50 Mi... Solo Backyard 50 Mile

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

Event Overview

The Cobscook Backyard Ultra takes place in Cobscook Bay State Park, located in Edmunds Twp, Maine. This event follows modified Backyard Ultra protocols where participants complete repeated loops within a set time frame. The course consists of vehicle-free park gravel roads and is marked with arrows at every intersection.

Participants can choose from several event formats:

  • Solo Backyard 50k
  • 2/3 person Backyard Relay 50k
  • Solo Backyard 50 mile
  • 2/3 Person Backyard 50 mile

Course and Format

For the 50k distance, runners complete a 5 km loop every hour for 10 hours. The 50 mile distance requires a 4.167 mile (6.706 km) loop each hour for 12 hours. A warning bell sounds five minutes before the start of each new lap. To stay in the event, participants must be at the start line exactly on the hour.

Participant Information

This is a self-supported event with no official aid stations, medals, or awards. Participants are responsible for bringing their own supplies, including food, drinks, chairs, and shelters. While no running water or showers are available on-site, there are multiple outhouses located along the course.

The park is closed to vehicles during the event dates. Participants must park outside the park gate on South Edmunds Rd and carry their equipment approximately 300 meters to the start and finish area. In case of ice, snow, or inclement weather, an alternative date is scheduled for May 3. Visit the organization's website for the most recent information.

50 mi
2/3 Person Backyard 50 Mile
50 mi
Solo Backyard 50 Mile
50 km
2/3 Person Backyard Relay 50k
50 km
Solo Backyard 50k