Alongside those of a dog and a human, I noticed these tracks of an eastern gray squirrel in weekend's snow. The squirrel was traveling in the direction towards the top of the picture.
Because of the unique pattern they create, squirrel foot prints are among the easiest tracks to identify (rabbit tracks are somewhat similar, though).
Note that the longer prints in the front are actually those of the hind feet. The drawing below explains how a squirrel creates its track pattern.
Drawing from Anonymous. Animal Tracks, Stackpole Co., 1954.