Brush, rocks, and folds in terrain certainly obscure your dog’s view of you. As bushes get taller and gullies deeper, they also block your view of him. All the waving tails and eager-dog behaviors in the world won’t help if your dog is invisible to you, hidden by brambles or boulders. Even on a good day, my dogs blend into the vegetation and are virtually invisible, so when I can’t find my guys, I climb. Not a lot, but enough to revise the geometry in my favor.