Over and Under the Snow by Kate Messner illustrated by Christopher Silas Neal*

This book is a favorite. We read it for the first time last winter and reread it many times that year!
A father and his daughter cross country ski and observe animal activity around them.  The father also shares what animals are doing under the snow.  There are illustrations that show the various animals under the  snow. In the author's note at the end, she shares further detail about each of the animals and their winter survival.

*Highly recommend.