When ever people go into the National Forests, the damage they do to the area is related to their access, their numbers and the length of time they can stay. The closer the public is to a National Forest, the more likely it will be filled with trash and painted with spray paint. The best thing for Nature is to restrict the public's use. The great forests can recover, but only if the people stay away for extended periods of time.
If more of the public were knowledgeable about what they should and should not do in the Forest, less harm would be done and more people could enjoy the resource and more of the plants and animals would healthier. If people translated that understanding to their own habitat, more people would be healthier.