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.
I would use this title with a winter or hibernation theme in Storytime, and it can certainly be used as an informational text for preschoolers to second graders.