Columbia subject headings:
Missouri River.
Yellowstone River.
Harvard subject headings:
Brothers--Juvenile fiction
Conduct of life--Juvenile fiction.
Missouri River.
Rivers--Juvenile fiction.
Sailing--Juvenile fiction.
Ships--Juvenile fiction.
Voyages and travels--Juvenile fiction
Yellowstone River.
Youth--Conduct of life--Juvenile fiction.
Princeton subject headings:
Missouri River.
Yellowstone River.