I put out a commercial "Trophy Rock" in a field in front of my house. I saw deer on it some when I put it out back in the summer. But since Fall arrived it has gone virtually untouched. However, I have always been told (by biologists) that salt/minerals are much more sought-after in the late winter and early spring... in part because bucks instinctively know they need minerals to aid antler development. And all deer need an extra "boost" when they're coming out of a lean winter. I'll definitely be beefing up my salt/mineral spot in February to see what happens.