More likely, though, the gray fox would have slipped far away before you were anywhere near being seen by him. He would not have been pressed to run up a tree – a feat he can easily accomplish, unique among North American canines.
No, the fox would have heard you coming from a long distance off. Sensitive ears, able to detect a mouse squeak at 300 feet, help make him a valuable pest-control device. Vermin like rats and mice are among its favorite foods and, as disease and tick carriers, one of our least favorite visitors.
Early in the morning, in the pre-dawn light, you may spot the long, low form of a gray fox winding around your lawn, ears up, nose down, a four-footed mousetrap.