Cobscook Backyard Ultra

Sun April 23, 2023 Edmunds Twp, ME 04628 US Directions


Solo Backyard 50k

$10 9:00AM EDT - 7:00PM EDT
5 spots left. Registration ends April 22, 2023 at 11:59pm EDT

2/3 person Backyard Relay 50k

$10 9:00AM EDT - 7:00PM EDT
4 spots left. Registration ends April 22, 2023 at 5:00pm EDT

Solo Backyard 50 mile

$10 7:00AM EDT - 7:00PM EDT
5 spots left. Registration ends April 22, 2023 at 5:00pm EDT

2/3 Person Backyard 50 mile

$10 7:00AM EDT - 7:00PM EDT
4 spots left. Registration ends April 22, 2023 at 5:00pm EDT

Race Website

Additional race information can be found at


Cobscook Bay State Park Road (off South Edmunds Rd)
Edmunds Twp, ME US 04628


Cobscook Backyard Ultra - 50K or 50 miles.  Sunday 23 April*

* Important Note regarding the date: the park will be contracting for some significant work removing damaged and dangerous trees. It is possible this work will be ongoing on 23 April.  If it is the event may be cancelled or postponed at short notice. 

The Event:  Come and run an easy 5 Km or 4.167 mile (6.706 Km) loops - just a stroll in the Park!  If you want to spend Sunday 23 April in the beautiful Cobscook Bay State Park running and walking your first, or a different kind of, 50 Km or 50 mile Ultra with a great group of people, then why not sign up and join the fun? Or bring 1 or more friends and split the distance between you as a team entry.

If you can run/walk 3.1 miles in 1 hour then do it again next hour, and then again for 10 laps/hours in total, then you can finish a 50K in 10 hours. Or if you don't think you can do it all alone, find a friend or two and divide it up as a Relay Team of 2 or 3, just so long as one team member completes each lap.

Or run/walk 4.167 miles each hour over and over again for 12 laps/hours in total for a 50 miler.  Again, do it as an individual or as a Relay Team of 2 or 3, just so long as one member completes each lap.

The course is on vehicle free park gravel roads and will be well marked with arrows at every intersection. The 4.167 mile loop will overlap with the 5K loop for the most part with an additional 0.57 Km out and back to make up the difference.  Course Map 50k click here - Course Map 50mi Click here

We’ll follow modified Backyard Ultra protocols – starting at 9am 50 Km runners will do one 5 Km loop, then do the 5K loop again at 10:00am, then again at 11:00am etc. through to starting the last lap at 6:00pm for 10 x 5K = 50K. When you finish a lap you'll likely have time to spare before the next one starts, so take a break, grab a drink/grub and wait for the next hour to come round. We will have a 5 minute warning bell before the start of the next lap. If you are not on the start line on the hour, because you haven’t finished the last lap or you've fallen asleep or whatever, then you are finished at however many loops you have completed.  The event ends after 10 hours so the furthest you can go is 50kms.

50 mile runners will start earlier, at 7:00am and do a 4.167 mile loop, then do it again at 8:00am, etc. as with the 50 K runners - every hour and starting the last lap at 6:00pm alongside the last lap for the 50 K runners.

Teams - in addition to individuals we will allow teams of 2 or 3 runners to compete.  So long as one of your runners is on the start line on the hour, and completes the loop, your team can continue.  This means you can participate without having to run all 10 laps, or even if you need to run off to do something else for a couple of hours.  It's up to you to organize your team. 

Note: if there is competition for places we will give first priority to individual runners, second to 2 person teams, and lastly to 3 person teams - so yeah, we're encouraging you to think big and ambitous - get out of your comfort zones!  

Timing:  We’ll have a clock and a timing sheet on-site – write down your own loop times. 

Not quite a Fatass style event – while largely a Fatass style event - no aid stations, no support, no medals or awards, just satisfaction for you (or your team) in completing the distance and a great sense of camaraderie as we all push ourselves, we do ask for a non-refundable donation of $10 to cover park entrance fees and some of our other basic costs.

You should Bring your own supplies, canopy, chairs, etc. be prepared for the weather conditions.   Also, please consider bringing something to share - we'll put out a shelter and table for this.  There are multiple outhouses along the course but no running water or showers.

Because the park is closed to vehicles until 15 May you will have to park outside the park gate on South Edmunds Rd. and carry your stuff from there to the Start/Finish area where we’ll all set up – it’s about 300 metres. You can bring a cart or wheelbarrow. Please do NOT block the park entrance.

Race Contact Info

If you have any questions about this race, click the button below.



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