Subject
Geology
162
Geology, Stratigraphic
72
Texas History
48
Texas
29
Paleontology
24
Frontier and pioneer life
21
Petroleum
14
Groundwater
12
Mines and mineral resources
11
Petroleum Geology
10
Natural gas
9
Petrology
9
History
8
Uranium ores
8
Mexican Americans
7
Texas Politics and government
7
Texas Social life and customs
7
Geology, Economic
6
Ranch life
6
Texas Description and travel
6
Texas Social conditions
6
Water-supply
6
Wells
6
African Americans
5
Ammonoidea
5
Art
5
Art collections
5
Cowboys
5
Indians of North America History
5
Lignite
5
Limestone
5
Sand
5
Texas Race relations
5
Facies (Geology)
4
Families
4
Folklore
4
Football
4
Governors
4
Mexican Americans History
4
Mexico History
4
Sandstone
4
Southwest, Old History
4
Alamo (San Antonio, Tex.) Siege, 1836
3
Art, American
3
Cattle trade
3
Cattle trade History
3
El Paso (Tex.) History
3
Frio Clay (Tex. and La.)
3
Geothermal resources
3
Homes and haunts
3
more ...