Columbia subject headings:
Harvard subject headings:
Panama-California Exposition (1915 : San Diego, Calif.)
Panama-Pacific International Exposition (1915 : San Francisco, Calif.)
West (U.S.)--Description and travel.
Yellowstone National Park.
Princeton subject headings:
Panama-California Exposition (1915 : San Diego, Calif.)
Panama-Pacific International Exposition (1915 : San Francisco, Calif.)
Union Pacific Railroad Company.
West (U.S.)--Description and travel.
Yellowstone National Park.