Bog Dog Running The Grim Reaper
10-mile estate loop at Grimsthorpe Castle run as 10, 40, 70 or 100 miles
| Distance | Ascent | Per km |
|---|---|---|
| 100 miles | 1,676 m | 10 m |
| 70 miles | 1,173 m | 10 m |
| 40 miles | 671 m | 10 m |
| 10 miles (day) | 168 m | 10 m |
| 10 miles (night) | 168 m | 10 m |
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No reviews of the Grim Reaper, and nothing on what people wore. Both are things no organiser publishes and every runner wants before they enter — how it actually went, and what was on your feet.
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Pick your distance
starts 10:00
What you’re in for
Every distance uses the same 10-mile loop around the Grimsthorpe Castle estate near Bourne: grass trail through old woodland, limestone tracks, quiet estate roads and a section of disused Victorian railway, passing the lake before finishing in front of the castle. Each lap has about 550ft of climb and no big hills, and the course is fully marked. The 100 and 70-mile races start at 7am with a 28-hour cut-off, the 40 at 8am (27 hours), the day 10 at 10am and a night 10 at 9pm. There is one aid station at mile 5, the race is cupless, and crews may only meet runners at the start and finish. Ultra runners must carry mandatory kit from 6pm, and you can camp on site Friday and Saturday.
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How to enter
Sat, 22 May 2027 · Not open yet · £35–£160
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Common questions
- The Grim Reaper offers 5 distances: 10 miles (day) (16.1 km), 10 miles (night) (16.1 km), 40 miles (64.4 km), 70 miles (112.7 km), 100 miles (160.9 km).