Apparently, they give you cakes at the end...
Copied this from their web site:
The Dentdale Run is a 14 mile 379 yard road race staged on the lanes around Dentdale, following a figure-of-eight course it winds up hill and down dale, starting and finishing at Dent Primary school.
The race is one of the most scenic road races in the area, and although only 14 miles long, it is regarded as a very tough circuit and many runners use it as a 'warm up' for the London Marathon. The run attracts around 500 participants each year with the top runners receiving prizes ranging from a week in a holiday cottage in Dentdale to beer from Dent Brewery. After race food and refreshments are also provided.
Organised by a local committee and sponsored by Dent Brewery, the Dentdale Run is a charity event with all proceeds going directly to Dent C of E Primary School.
"Very tough". Hmm... that'll teach me to do my research before entering these things. Runner's World describes it merely as "undulating". Gets some good reviews on here though. Plus, the distance is a novelty factor.
Shame I'll be driving, so won't get to sample the beer.