Here is the perfect book for parents and grandparents who are worried that their loved ones are suffering from nature deficit disorder — having little or no contact with the world of trees, stones, animals, and rivers, often because they are spending all their time with media and electronic devices.

A father and his son are on their skis going slowly through the forest. He tells the boy that "under the snow is a whole secret kingdom, where the smallest forest animals stay safe and warm." While the boy tries to imagine the underground world of deer mice, slumbering frogs, busy squirrels, and foraging voles, he is told by his dad to keep his eyes open for tracks of other animals such as red foxes who do not have the luxury of a sanctuary under the snow.

Kate Messner, a middle school teacher and author of several books for young readers, has fashioned an edifying picture book for children from preschool to grade 3. The text is admirably supported by the illustrations of Christopher Silas Neal. Over and Under the Snow is a wonder-inducing book with data on what the scientists call the "subnivean zone." When next you are in a snowy landscape, take your child or grandchild for a walk in this wonderland.