Subject
Operas
1,186
Colorado History
241
Colorado
226
Frontier and pioneer life
215
Geology
211
Songs (High voice) with orchestra
156
Water resources development
120
History
103
Colorado Description and travel
95
Indians of North America
90
Mines and mineral resources
88
Cooking
86
Water-supply
71
Cooking, American
65
Indians of North America Antiquities
65
Songs (Medium voice) with orchestra
59
Colorado Antiquities
57
Railroads
55
Natural history
54
Colorado River (Colo.-Mexico)
49
Excavations (Archaeology)
41
Gold mines and mining
41
West (U.S.) History
41
Grand Junction (Colo.) History
40
Indians of North America Wars
39
Oil-shales
39
Songs (High voice)
39
Mines and mineral resources History
37
Oil-shale industry Environmental aspects
37
Geology, Stratigraphic
36
Railroads History
36
Ute Indians
36
Colorado History, Local
34
Irrigation
34
Little Bighorn, Battle of the, Mont., 1876
33
Piano music
33
Cowboys
32
Ranch life
32
Vocal duets with orchestra
32
West (U.S.)
32
Oil-shale industry
30
Rocky Mountains
30
Denver (Colo.) History
29
Uranium ores
29
Grand Junction (Colo.)
28
Water rights
28
Cattle trade
27
Denver (Colo.)
27
Narrow gauge railroads
27
Pioneers
27
more ...