Douthat State Park is located just outside Clifton Forge, VA in the little town of Millboro. It's about an hour north of Roanoke on US 220.
The mountain bike trails there...well, they're just outstanding. If you haven't been there yet, pack up the car and go now. It's that good.
Douthat offers more than 40 miles of trails and most are open to mountain bikers. There are also several different options for lodging including tent campsites and cabins. There's a restaurant on site, a camp store selling essentials, and if all that's not enough...there's also a lake that offers swimming and boating during the warmer months.
The Virginia Department of Conservation and Recreation has a great website with all the particulars about the park.
For a map of the trail system, click HERE