Cobscook Backyard Ultra

APR
26
2026
The Cobscook Backyard Ultra is a self-supported loop race in Cobscook Bay State Park. Runners can tackle a 50k or 50-mile distance solo or as a relay team, starting a new loop every hour. The event emphasizes community and self-sufficiency, with a $15 entry fee.
Sun 26 Apr 2026
Solo Backyard 50k 2/3 Person Backyard Relay... 2/3 Person Backyard 50 Mi... Solo Backyard 50 Mile

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Event Overview

The Cobscook Backyard Ultra is a timed loop event held at Cobscook Bay State Park in Edmunds Township, Maine. The event offers four race formats: a Solo Backyard 50k, a 2/3 Person Backyard Relay 50k, a Solo Backyard 50 Mile, and a 2/3 Person Backyard 50 Mile. The entry fee is $15 per person.

Course and Format

The course consists of repeated loops on vehicle-free gravel roads within the park. Participants aiming for a 50k run a 5 km loop every hour for 10 hours. Participants aiming for a 50 mile run a 4.167 mile loop every hour for 12 hours. The courses are well-marked with arrows, and the longer loop overlaps with the shorter one for most of its distance.

The event follows modified Backyard Ultra rules. A new loop starts every hour on the hour. If a participant or a team member is not at the start line for the next loop, their race is over.

Event Details

The event is largely self-supported. There are no aid stations, medals, or awards. Participants are responsible for bringing their own supplies, food, water, and shelter. A communal shelter and table will be provided for sharing items. There are outhouses along the course but no running water or showers.

Parking is available outside the park gate on South Edmunds Road, requiring a 300-meter walk to the start/finish area. Participants are encouraged to bring carts or wheelbarrows for their gear.

Logistics and Registration

Registration opens on February 16, 2026. The event date is April 26, 2026, with an alternative weather date of May 3, 2026. The event is subject to park permitting and construction schedules. An announcement regarding registration will be sent in mid-February. 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
Solo Backyard 50k
50 km
2/3 Person Backyard Relay 50k