Columbia subject headings:
Hudson River Valley (N.Y. and N.J.)
Idlewild (N.Y.)
Harvard subject headings:
City and town life--Juvenile fiction
Hudson River Valley (N.Y. and N.J.)
Idlewild (Cornwall, N.Y.)
Idlewild (N.Y.)
Letters--Juvenile fiction.
Natural history
Trees--Juvenile fiction.
Princeton subject headings:
Hudson River Valley (N.Y. and N.J.)
Idlewild (N.Y.)