Oasisbob mentioned USFS (Forest Service) campgrounds. Those are federal lands, not state. The suggestion to call the office of the national forest where you want to camp to check the rules is the best one. We have about seven different national forests in Oregon. Presumably they all have the same rules but there may be local exceptions. The forest service does have an acronym-laden plan that defines motor vehicle use in the forests. I know in some forest service campgrounds, it is either allowed or not allowed to start the engine of an ATV in the campground (varies by campground).