Those familiar with boondocking (RV camping outside a developed campground in remote locations) are familiar with the US Forest Service 300 foot dispersed camping rule. That rule stated that you could camp within 300 feet of a road.
What a great rule it was too.
Rules are a changin' and your favorite US National Forest has, or will soon make changes that may force you change your travel plans. New rules in effect in several forests state that motorized dispersed camping is permitted within one vehicle length of approved roads. There are a few quid pro quo to go with it such as being a safe location to be off the road etc.
A couple important things to keep in mind here. The latest approved travel management plan for the area you are planning to camp is what governs where you can go, not what you are accustomed to or even numbered roads you "think" should be open to travel. What is on the current official travel management map available for free for the area you are camping/traveling is what governs where you can go.
Here is a link to the main USFS page regarding travel management maps. My experience with looking through the Pike National Forest maps was it takes some digging to find the travel management maps for the specific area I was looking for on line. The information is there, I just had some trouble finding it.
US Forest Service Travel Management Maps
So far, I've got a lot more questions than answers to my emails to the US Forest Service. I believe it's going to take a personal visit to the law enforcement office that covers the area I wish to camp for definitive answers about their enforcement practices in specific areas. I believe it will be in your best interest to get informed about the new travel management and motorized dispersed camping rules for the areas you wish to boondock in national forests.