I cycled the Blue Ridge Parkway and Skyline Drive recently. I applied for and received a "back-country permit" to basically camp anywhere in the parks as long as I was 1/4 mile off the road. They don't even allow people to push a bicycle on the AT for 1/4 mile... or on the fire roads. At the fire roads, there are signs that say "Backcountry-no bicycle allowed" I'm currently riding the C&O and it's perfect for bikes