I have previously written about national forest campgrounds, an affordable and enjoyable way to camp without the crowds and expense of commercial and national park campgrounds. If your rig has good boondocking capability, there's an even less crowded – and even cheaper – alternative: dispersed camping in national forests.
While our boastful neighbors to the north extoll the virtues of their Crown lands, there's plenty of space right here in the US of A where free camping is also available, at considerably less chance of frostbite, bug bite, polar bear bite, fuel price bite, etc.
You heard it- free. No tax, no handling charges, no reservation fees. As a matter of fact, you don't even have to sign up for it. If you're parked, you're registered. There's usually a 14 day limit, and you can't camp within a certain radius (usually five or seven miles, sometimes ten) from the last placed you camped, or come back within a certain period, usually five or seven days, but that's just to discourage people more intent on homesteading than camping. All you need to know is what areas of the national forests allow dispersed camping.
Most of this stuff is out west – there's limited dispersed camping in Maine and Michigan's UP, but it's generally unavailable in the east. Like the national forest campgrounds, there's no one place online where you can go look up information on particular areas of the National Forests where dispersed camping is allowed. There is some information online for dispersed camping in certain national forests like Payette NF in Idaho (top photo, beautiful place), but these are the exceptions. Most of the information is kept “behind the counter” – in ranger stations.
Each national forest has several ranger stations, and their addresses and phone numbers are on the web pages for that particular forest. Drop by or call them and ask about dispersed camping. They will give you a map with all the forest roads marked on it, and indications of where dispersed camping is allowed. These areas are usually marked by dots on each side of a road in the maps I have been given. They will also tell you road conditions, whether the road you're looking at is suitable for your vehicle (actually, the road doesn't care much whether you think it's suitable or not – it's more a matter of whether your vehicle is suitable for the road), hotbeds of activity by those infernal off-road vehicles to avoid, recent bear and mountain lion activity in the area, any burn restrictions in effect, fire permit procedures, and other interesting stuff like that.
Armed with your map, set out and claim your spot. Don't just plunk down in the first nice area you find, or you'll probably soon have company since you're sitting in the most accessible spot. Drive around a bit. Think about where the sun's track will be if you have solar panels, and whether you can hit the satellites from your spot if you have TV or internet dishes. Also, make sure your spot is in compliance with the rules printed on the map or told to you in the ranger station. There are sometimes restrictions on how close you can be to open water, or how close or far from a road you can be. If you're in a flash flood area, you don't want to be anywhere near a watercourse, even if it's bone dry right now. If you see signs of bear activity (overturned rocks, scratches on trees, etc.) you might want to shop around a bit more. The problem with bear wrestling while dispersed camping is that there's nobody to tag out with.
Your map will also contain the locations of developed campgrounds. Ask or look up which of these have water so that you can drop by and replenish your supply when you get low. There are rules for water and waste disposal for tent campers – since you're a self-contained RV, you don't have an excuse for sleazing out and failing to pack out everything you pack in. Leave the forest as nice or nicer than you found it. This is not a campground with a dumpster and bathhouse and all that stuff.
Give dispersed camping a try if you have the boondocking capability to do it comfortably – I put a lot of extra effort (and money) into outfitting mine so that I would have all the comforts of home without requiring any more infrastructure than a level place to park, and it has paid off handsomely. Dispersed camping gives you that most precious of commodities in this urbanized, modern world – solitude in a beautiful natural setting. I am writing this while camping in the Custer National Forest southwest of Red Lodge, and I haven't seen a soul since we drove in here. It's just me and the mountains and the streams. One hundred and thirty-six years ago, Chief Joseph and his people gave the US Army the slip, coming down this very valley I'm camping in. Like me, the chief had had a bellyful of so-called civilization, and didn't want any company. The chief was a wise man – it's an excellent place for that.
edit 7/8/13: I have discovered an excellent online source for the maps that designate dispersed camping in national forests – they're called Motor Vehicle Use Maps (MVUMs) and are primarily used to tell the noisy two-stroke crowd where they can and can't drive, but also have valuable information for us more spiritually advanced types. Go here: http://www.fs.fed.us/maps/forest-maps.shtml and pick the forest you are interested in. The individual forest sites vary, but look for MVUMs as PDF downloads. Look for the dots on either side of the road – that means it's OK to camp there. The map may also contain information about minimum and maximum distances from the road you can camp, plus how close to water you can camp. A little poking around will save you a trip to the ranger station.