I go to DP quite a bit, it's some of the best trail riding in Georgia, when it's not too wet! The red and blue trails are one-way, bike only, and the green trails are for bikes and quads (also one-way). It'll take you a good 2-3 hours to run the red/blue trail system, which is about 80% tight woods and some hills. It's $25 a day to ride (for adults, less for kids) and if you go to the Durhamtown web site and find the tiny "coupon" link under Dirt Bikes, you can print-off a $5 discount.