get him gobbling big time, then shut right up. Decoys are good, but i dont recommend them. I know you see on tv all the time birds running right into the decoy and stompin the **** out of it, but not around here. Birds around here are very "stressed" to say the least. The natural thing that happens in the woods is that the hen is suppose to go to the gobbler anyways. So if that big gobbler sees the hen (the decoy) or hears you calling, and he is in seeing distance, he will usually hang up everytime. Get him screaming coming in, and then at about 100 to 150 yards, before you can see him, shut right up. He will come in looking, thinking that the hot lady is heading away from him. Remember, the older the bird, the smarter he is. It takes wits to outsmart a big ol tom.
As far as crossing barriers, believe me, if that gobbler is fired up, he will fly across the damn grand canyon. But if it seems like he really wants to stay on the other side (other side of a ridge like you said), get over there with him. Granted that you dont get to close, but definitly get where he wants to be. Greater chance of rolling him over that way.
Stick with it, and the best of luck to you.