Columbia subject headings:
Frontier and pioneer life--South Platte River Valley (Colo. and Neb.)
South Platte River Valley (Colo. and Neb.)--Description and travel.
South Platte River Valley (Colo. and Neb.)--History.
Trails--South Platte River Valley (Colo. and Neb.)--History.
Harvard subject headings:
Frontier and pioneer life--South Platte River Valley (Colo. and Neb.)
South Platte River Valley (Colo. and Neb.)--Description and travel.
South Platte River Valley (Colo. and Neb.)--History.
Trails--South Platte River Valley (Colo. and Neb.)--History.
Princeton subject headings:
Frontier and pioneer life--South Platte River Valley (Colo. and Neb.).
South Platte River Valley (Colo. and Neb.)--Description and travel.
South Platte River Valley (Colo. and Neb.)--History.
Trails--South Platte River Valley (Colo. and Neb.)--History.