Looks ideal terrain

http://www.britishpathe.com/video/cyclists-beat-runners

There's a local race that runs every boxing day, runners vs riders. It's pretty muddy and there's trees to get over etc. probably about 100 people or so taking part - normally a CX bike wins it - but every year the top 10 has at least 1 runner in it. One year I finished about 3 seconds in front of a runner - and only coz I sprinted right at the end - that was embarassing

(race lasts about 20 mins mind, not 20 hours like the BB200)