The New River Gorge National River may allow mountain biking. Public
comment period is open, but the public has wanted this area opened for
mountain biking for decades.

http://www.register-herald.com/todaysfrontpage/x2039226099/SPECIAL-REGULATION-Gorge-biking-trails-open-for-comment

The park will have to look at the impact of mountain biking but based on
previous studies in other parks, in looks like a slam-dunk. No study on
the impact of different trail users has ever shown that mountain biking
has more of an impact than hiking on trails or wildlife.