Columbia subject headings:
Art and photography.
Art, American--20th century.
Cartography in art.
Conceptual art.
Earthworks (Art)
Harvard subject headings:
Cartography in art.
Conceptual art--United States.
Earthworks (Art)--United States
Princeton subject headings:
Cartography in art.
Conceptual art--United States.
Earthworks (Art)--United States.