I stopped by Keystone State Park for a look and snack break. It had been a few years since I'd been camping here. Nice enough camping, but bring your ear plugs because there are obviously trains in the local area that you can hear throughout the night.
Just below the Keystone Lake dam there is a place for ORV riding. It is primarily sand, so the majority of visitors are on four wheelers. I've seen several 4x4s and a couple sand rails out here playing as well. It's not the best place to ride a dirt bike, but does in a pinch. And actually if you find the trails along old highway 51, riding there you will find a lot more dirt and mud trails in the woods.
Here's the only shot I grabbed of the area.