Unable to keep up with the cattle drive, Molly the mare is left behind to have her foal on the rim of Black Oak Canyon. The lonely mare and her newborn are forced to contend with many dangers before they are safely retrieved by the ranch herd. The animals of the wilderness pose their challenge one by one -- the rattlesnake, coyote, the mountain lion and bear. The forces of nature converge too -- storms, and floods, etc., but Molly and her foal come through safely. There is little originality in the storyline. The strength of the book lies in the author's admirable black and white and one color drawings of animals in action and in his subtle portraysl of animal survival in the face of nature's threats.