I have 2 properties that I am about to give up on. Both are excellent looking and I know there are many coyotes there. No matter how good they look, I have terrible luck there. On the other hand I have a couple places that produce about every third time I call there. I limit all my places to 2-3 sets per year to keep the pressure down. You might try shotgunning on a full moon night over snow. My cousin in Nebraska has great luck with night calling. You might want to make sure it's okay with the land owners. I had a bad experience night hunting years ago. Had a farmer claim to be holding a pistol on me behind his truck door. I didn't really feel like arguing with him. I had permission to hunt on his neighbor, but he thought I was poaching or shooting at his cows or something like that. Even more impotant, keep expanding your hunting properties. You can't have too many.