If turkeys only walked up hill then the hilltops would be covered with turkeys. The problem is that from above he has a commanding view of your location and he don't see no hen. It is easier to fool him if you can move along the ridge and come up equal to his level, then call him along the ridge. If you cut a good deer trail, old road bed or other line running along the ridge set up on it. You can be assured he knows about it and it will lead him to you.
I talked to a fishing pro one time and he said "I don't make a single cast to a piece of structure till I am in the right position to do so". Good advise for turkey hunting too.