This is a field guide to the animals you didn't see. With it you may read the record of the deserted field, the snowy clearing, the dusty trail, and the riverbank, understanding the life of the creatures who have passed that way. It is the most authoritative work in this field since Ernest Thompson Seton, and the most complete. It includes all the mammals of North America as well as many birds and insects. There are more than 1000 illustrations and there is a simple key to the tracks themselves which enables the reader to place quickly any animal track that he comes across.