Second that advice on the Cranberry! I live up in NE Ohio and have relatives that live in Lewisburg (WV) so I frequent the Monogahela as much as I can when I am visiting.
Additionally the little mountain feeder streams contain Brookies so you won't have any shortage of fishing.
Elk Springs Resort, like Seth said, is also a good river to fish but not as remote as the Cranberry, and not as big.
Elk Springs Resort