Five Mile Pass is a very busy ATV riding area. If you're going to be in the Lehi, Utah area, definitely make this a stop along your ATV riding way. Interestingly, this is an old Pony Express Route, but in reality, more recently, it has served for sheep grazing on BLM land for many years.
The ATV trailhead is located on the north side and is nearly an eighth of a mile wide and this is a very busy area more often than not, and very busy can equal hundreds of riders. Riding your ATV in this trailhead area (besides using it to get on the ATV trail) is discouraged. Do be aware there are no public restroom facilities on this site. The closest public restroom is in the nearby town of Cedar Fort.
Dispersed camping is permitted on these ATV trails, there are dense forests of cedar trees that are ideal for this purpose. Just remember to follow the standards put forth by Treadlightly and if you bring it in with you, pack it out.
There is a great area to practice going through gullies next to the rail trail a few times, because you will find similar obstacles out in the actual ATV trail. A little practice and getting your technique for getting through the gullies may save you some frustration out on the ATV trail.
The ATV trails are clearly marked and the area in the North, is a mish-mosh of public and private lands. Mostly they are considered underground rights and belong to people who own mineral rights. The rules are simple, if you see a private property sign, do not drive on the area with your ATV. The public lands are open for your ATV riding pleasure, go around privately owned areas.
There are a load of fun riding areas throughout these ATV trails, gullies in the North, low areas to the South and in the east there are some great low sloping rocky inclines to climb. Enjoy your ATV ride at Five Mile Pass!