I agree with the others that it all depends on the bird. I've seen hot birds jump deadfalls, fences, and narrow creeks. I've also seen them go up and down ridges. When I started turkey hunting, I was always told that they never did that. Apparently, they do. In sum, you should still be able to get a bird to play if you're out at the right time.
Another thought... do you know how many hunters are on that adjacent property? Your other best bet may be to let them pressure some of those birds off their property and on to yours. Maybe you should stay out of that particular area for a week or two if you know they're hunting.