Subject
United States History
20
United States Politics and government
12
Water rights
12
Legislators
11
United States
11
United States Discovery and exploration
11
History
10
Indians of North America Wars
8
Water Law and legislation
8
Explorers
6
Colorado Politics and government
5
Little Bighorn, Battle of the, Mont., 1876
5
Soldiers
5
United States History Regimental histories
5
West (U.S.) History
5
Colorado
4
Colorado History
4
Colorado River (Colo.-Mexico) Description and travel
4
Frontier and pioneer life
4
Oil-shales
4
United States History Campaigns
4
Uranium ores
4
World War, 1939-1945
4
Baseball umpires
3
Colorado River (Colo.-Mexico)
3
Colorado River (Colo.-Mexico) Discovery and exploration
3
Grand Canyon (Ariz.)
3
Indians of North America
3
Indians of North America Government relations
3
Irrigation
3
National parks and reserves
3
Oil-shale industry
3
Railroads
3
Southwest, New Description and travel
3
Travel
3
United States Civilization
3
United States Foreign relations
3
United States History Causes
3
United States History State & Local West
3
Water resources development
3
Water-supply
3
Water-supply Government policy
3
West (U.S.)
3
West (U.S.) Description and travel
3
West (U.S.) Discovery and exploration
3
Artists
2
Authors, American
2
Capitalists and financiers
2
Cattle
2
Cattle trade
2
more ...