Over and Under the Snow by Kate Messner with art by Christopher Silas Neal shows the "secret kingdom under the snow." As a father and child ski through the landscape the forest animals that live there are revealed. This nonfiction book is packed with real information about animals during the winter.
The illustrations in this book were rendered in mixed media. Neal describes the process with the author on his website. The muted tones lend an authentic nature to the story. I always enjoy finding out how the illustrator makes his art.
Kate Messner's website has great gems of information and she shares writing tips on her blog.
This book would be a good way to introduce how animals live through winter for Preschoolers to 2nd grade.