["JUVENILE NONFICTION \/ Biography & Autobiography \/ Literary","JUVENILE NONFICTION \/ Lifestyles \/ Country Life","JUVENILE NONFICTION \/ Science & Nature \/ Environmental Conservation & Protection","JUVENILE NONFICTION \/ Science & Nature \/ Environmental Science & Ecosystems","Juvenile Nonfiction\/Biography & Autobiography - Literary","Juvenile Nonfiction\/Lifestyles - Country Life","Juvenile Nonfiction\/Science & Nature - Environmental Conservation & Protection","American authors;Biography.","Authors, American - 19th century","Biography & Autobiography","Biography & Autobiography - Literary","CHILDREN'S BIOGRAPHY","CHILDREN'S BIOGRAPHY \/ LITERARY","CHILDREN'S ENVIRONMENTAL STUDIES","CHILDREN'S NATURE","Country Life","Easy Non-Fiction","Environmental Conservation & Protection","Environmental Science & Ecosystems","JUVENILE","JUVENILE NONFICTION","JUVENILE NONFICTION \/ Biography & Autobiography \/ Literary","JUVENILE NONFICTION \/ Lifestyles \/ Country Life","JUVENILE NONFICTION \/ Science & Nature \/ Environmental Conservation & Protection","JUVENILE NONFICTION \/ Science & Nature \/ Environmental Science & Ecosystems","Juvenile Grades 1-2 Ages 6-7","Juvenile Nonfiction\/Biography & Autobiography - Literary","Juvenile Nonfiction\/Lifestyles - Country Life","Juvenile Nonfiction\/Science & Nature - Environmental Conservation & Protection","Lifestyles","Lifestyles - Country Life","Literary","Natural history - Massachusetts - Walden Woods","Natural history;Walden Woods (Mass.).","Picture Book","Science & Nature","Science & Nature - Environmental Conservation & Protection","Solitude","Thoreau, Henry David - Homes and haunts - Massachusetts - Walden Woods","Walden Woods (Mass.) - Social life and customs","Wilderness areas - Massachusetts - Walden Woods","Wilderness areas;Walden Woods (Mass.)."]