I've got a lot of respect for what a Deer can smell. Many times I could tell from their demeanor when I was busted. Many times they knew I was around at four hundred yards, not exactly where I was, just that I was around someplace. At forty yards or so it was panic time.
I watched two trophy Bucks, shoulder to shoulder making a bee line (straight as an arrow) across open farm land, late morning maybe 10 A.M. They were moving right on out, not in a panic but covering a lot of ground. They were coming in from a neighboring lease and heading straight for a spot I had heard a Doe Rut bleating early that morning, she always hung out around that same spot. I checked the distance they covered on Google maps .85 miles. Just the part of the run I saw, you can add another quarter of a mile to neighboring lease border. That my friends is a good nose.