Columbia subject headings:
Kansas--History.
Oklahoma--History.
Texas--History--1846-1950.
Trails--Kansas--History.
Trails--Oklahoma--History.
Trails--Texas--History.
Harvard subject headings:
Kansas--History.
Oklahoma--History
Texas--History--1846-1950
Trails--Kansas--History.
Trails--Oklahoma--History.
Trails--Texas--History.
Princeton subject headings:
Kansas--History.
Oklahoma--History.
Texas--History--1846-1950.
Trails--Kansas--History.
Trails--Oklahoma--History.
Trails--Texas--History.