I would highly recommend Rock Run for all ages of ATV riders. It's a rather pleasant 4 hr drive from Balto and DC. They have all types of well-maintained trails, as well as primitive camping. Check out their website.
You don't need a 4wd ATV, and I've seen plenty of sport quads and dirt bikes.
Check out Prince Gelatzin (spelling) state park. They have clean showers, a beach, etc. It's about 15 minutes from Rock Run.

 

thanks for sharing...will check it out