MVUM (Motor Vehicle Use Map)

Every national forest publishes its own MVUM, a requirement of the 2005 Travel Management Rule. It shows the Forest Service roads, trails, and areas designated open to motor vehicle use, broken out by vehicle class -- highway-legal vehicles, vehicles 50 inches or less, motorcycles -- along with any seasonal dates and distance allowances. It is free: download the PDF or pick up a paper copy at a ranger district office. Most are geospatially enabled PDFs, so the Avenza Maps app will put a you-are-here dot on the map with no cell signal, which is the whole ballgame when you are standing at an unmarked fork forty miles from pavement.

For your trip, the MVUM answers two questions. First: may I drive this? Routes not shown are not open to public motor vehicle travel -- the Willamette National Forest puts it flatly, "If a Forest Service road or trail is not on this map, public motor vehicle use is prohibited." Second, and this is the part people miss: on many forests it also answers may I camp here? Federal rule 36 CFR 212.51(b) lets a forest permit limited motor vehicle use within a specified distance of certain roads solely for dispersed camping or for retrieving a legally taken big game animal. Where a forest does that, the MVUM is what marks those corridors and the distance -- commonly up to 300 feet from the road on forests like the Willamette and the Black Hills.

Here is the catch, and it is a big one: that distance is set forest by forest. The regulation says "a specified distance" and never names a number; 300 feet is simply the figure a lot of forests landed on. Other forests mark no camping corridors at all, in which case the MVUM tells you only where you may drive and a separate forest order governs where you may camp. Do not carry one forest's rule across a boundary. Check the legend of the specific MVUM you are on -- the legend is where the vehicle classes, seasons, and camping distances actually live.

Three more honest limits. The MVUM is not a road-condition map: as the Black Hills National Forest warns, routes shown open to a vehicle class "do not mean they are maintained for or suitable for travel using those vehicles" -- open on paper, impassable in mud is a normal outcome. It is black and white with no topography, so it is meant to be used alongside a Forest Visitor Map, not instead of one. And it gets revised to fix errors and reflect new travel decisions, so last season's PDF sitting on your phone is not the current legal document -- re-download before a trip. Getting it wrong is enforceable: 36 CFR 261.13 prohibits operating a motor vehicle other than in accordance with the designations, with exemptions for things like aircraft, watercraft, over-snow vehicles, and emergency response. Free map, downloaded in two minutes, and it is the difference between a legal camp and a citation.