Action Sports in Athens has real good elevation changes and is an extremely fun track.
COCR in Sugar Grove is also a really fun track with good natural elevation changeups.
It looks as though MX213 at St Clairsville Ohio has cool rolling hills. ( I haven't been there)
Scenic Highland had great elevation changes. (closed)
Honda Hills had awesome elevation changes. (closed)
Wild Wilderness in Athens had some of the biggest elevation features I've seen. (Closed)
I've always thought that if a piece of land has enough elevation features to it, it would take very little to race on it. Only use equipment for challenge sections like Rhythms or whoops, and to fine tune jump faces. Other than that, just begin as a grass track and let the track develop itself. The rougher the better. (Who needs good flow
ha ha!) After all, they're dirt bikes.