Grim Reaper Running Festival

MAY
22-23
2027
A multi-distance trail event at Grimsthorpe Castle using a 10 mile loop with 10 to 100 mile options plus a 100 mile relay on mixed grass, woodland and limestone terrain.
UTMB 50K/100K/100M 100 miles 70 miles 40 miles 10 miles

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The Grim Reaper

The Grim Reaper is a multi-distance trail running event held at Grimsthorpe Castle, Bourne, organised by Bog Dog Running. Every race uses the same 10-mile loop around the estate, with solo distances and a team relay available. All finishers receive a medal and trophies are awarded to the top three male and female finishers in each solo race and to the winning relay team.

The 10-mile loop runs across grass trails, ancient woodland, limestone tracks, quiet estate roads and along a disused Victorian railway line, skirting the estate lake and returning to the castle. The course is fully marked, undulating with about 550 ft of climb per lap, and trail shoes are recommended. There is an aid station at mile 5 with water, limited snacks and a toilet. The event is cupless so participants should use their own cup or buy one on site. Fully qualified medics are on site throughout, and a well-stocked running shop is available at the event.

Distances offered

  • 10 miles day and night options
  • 40 miles four laps
  • 70 miles seven laps
  • 100 miles ten laps and 100 mile relay

Race rules and support are strict: pacers are permitted from mile 50 for the longer solo races, crew access is limited to the start and finish, dogs are allowed only in the 10-mile races and must be on a lead, and minimum age limits apply for each distance. Mandatory kit is required for the ultra distances during night hours and includes basic safety, lighting and waterproof items. Visit the organization's website for the most recent information.

100 mi
100 Miles Solo
100 mi
100 Mile Relay
70 mi
70 Miles Solo
40 mi
40 Miles Solo
10 mi
10 Miles Solo Night
10 mi
10 Miles Solo Day

Events nearby

An element themed loop race at Thorpe Meadows offering lap-based distances from 5 km up to ultra, flexible start within a set window, and a collectible medal as part of the four-event Elements Series.
A timed multi lap event at Ferry Meadows on a 5.3 km traffic free loop, run in 4 or 6 hour formats with an aid station each lap and HQ at the Lakeside Centre.
A 15 mile riverbank and road run across the Lincolnshire Fens from South Kyme with drinks stations, marshals and post run refreshments.
A lapped Remembrance Run at Ferry Meadows on a 5.3 km traffic-free loop, offered in 4- or 6-hour formats with an aid station each lap.
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