Trail Runs and "Fat Ass 50"

An article in the New York Times today about trail running brought up an interesting fitness area that I would think a lot of people like.  If you like to get outdoors and get in the backwoods, why not try some trail runs?  A "Fat Ass 50" is a 50K run and far longer than any beginner should try, but trail runs in general might be a good mix up for your summer workouts.  Here are a few places that might help you get started to finding these "Fat Ass 50's":

Trail Monster - Has some options for groups runs and upcoming events in the New England area.

Fat Ass Trail Run - Race info for the run in Batawa Ontario.

Endurance Buzz - Sign up to get your regional guide for trail runs in Texas, Arkansas, Oklahoma, Lousiana, and New Mexico.