You're probably thinking what is a cyclist doing trucking through the woods without pedals between his legs. One word sums it up - challenge.
Chilly Cheeks trail run is another perverse product of Ron Horne, race organizer from http://www.pretzelcitysports.com/ based in the Reading, Pa area. There's a whole series of them with wacky names, Chilly Cheeks, 7 miles or so of hills hills, hills.
Starting off with 462 runners, the 27 degree January day was perfect for a run through the woods. The fun ends when ascending one of the many long hills that has everyone panting with delight. Some ice and snow made for some interesting footing but heck, if I wanted safe conditions I'd go for a run around my block.
All in all got through the run intact and even saw the famous Reading pagota (I ran past it previously and didn't notice the 10 story pagota due to my delerious state). Only fell once witch is good.