Keepstone Farm is actually in Berryville, but it's not a horrible drive out there from Fall's Church. It's very scenic, actually, and lovely just for the drive alone.
You have to contact the trainer there, Susan Rhoades, to set a time and date to come out for lessons. She works Border Collies but she has titled other breeds of dog as well. Her contact email is posted on the "About Susan" page, and Carolina also put it into her post for you.
I had Abby's herding test done at Keepstone Farm and it was a really nice experience. I know a lot of people drive pretty far to train with her. Unfortunately, we're about to move, so we actually won't have the opportunity to train with her and get more into herding at this point.