If you are looking for a low-use 4-wheeling trail, the Bear Creek is located in the Pike National Forest has light traffic. The trail is open to hikers, motorcycles, horseback riders and mountain bikers but does not see a lot of use due to the difficulty level.
This is a very difficult 4-wheeler trail and although it is only 7 miles long, even seasoned 4-wheeler riders will find it one very challenging ride. Because this is a very challenging 4-wheeler trail to ride, be safe and always use your most conservative judgment when mapping out terrain on which to ride your 4-wheeler. To give you a basic idea of the sheer steepness of this road, this trail climbs from 6400 feet to 8000 feet within a mile and a half span of road. This is a very steep grade and should only be attempted by the most experienced of 4-wheeler riders.
These trails are extremely slippery when wet, if the trail seems wet, it might be best to not ride that day, as you need the ultimate in grip and traction on your tires to get up this 4-wheeler trail. Also, it's never a good idea to ride alone but never go riding by yourself on an extremely difficult trail as this one. Always tell someone where you are going to ride your 4-wheeler and when to expect you back from your 4-wheeler ride. Leaving a map of your route is also smart.
Forest Service regulations require that you have a 4-wheeler permit displayed on your 4-wheeler in a clearly visible spot and that you have a muffler and spark arrestor installed on your 4-wheeler prior to riding. If you are under the age of 18, you are required to wear a DOT approved helmet, and as you know, no matter what your age it's just a good idea!
Make sure your 4-wheeler tires have good grip and if you have doubts of their tread, replace them before you ride this area. It's challenging and a definite feather in your proverbial riding cap to complete.