There is no basis that I can see to not allow concealed/carry in the state or national forest in VA. It's not like a person will use the gun to shoot wild game with, as the vast majority of concealed/carry guns are very impractical for the task. If you are worried about state property getting "shot up" in fun, I would argue that most, if not all, of the concealed/carry individuals value their rights under the constitution to defend themselves and wouldn't consider throwing that away on a whim and a bit of target practice.
Times have changed in a bad way these days. Just look at the yearly headlines of people killed/raped on hiking trails and the like. How would you like to be the one in the shoes of the victim, or watch as your wife/daughter/girl friend gets raped from some whacko, just because the government showed no trust in you to carry a gun in your defense and the possible defense of others?
Responsible people will do the responsible thing, whether their hands are tied with anti-gun legislation or not. Give them a chance to be responsible while protecting themselves, too.