History 21 Indians of North America 15 Depressions 9 Droughts 7 Dust storms 7 Dakota Indians 4 Dust Bowl Era, 1931-1939 4 Frontier and pioneer life 4 Social conditions 4 Wars 4 Farmers 3 Human ecology 3 Antiquities 2 Description and travel 2 Environmental conditions 2 Farm life 2 Indian art 2 Migrant labor 2 Natural history 2 Oglala Indians 2 Religion 2 Agricultura 1 Agriculture 1 American Indians 1 Antiquités 1 Archaeology 1 Archéologie 1 Art indien d'Amérique 1 Arts, American 1 Cartoons and comics 1 Cheyenne Indians 1 Children of migrant laborers 1 Depresiones 1 Droogte 1 Education 1 Environmental aspects 1 Fires 1 Fishing 1 Folklore 1 Freshwater fishes 1 Gold discoveries 1 Government relations 1 Grassland fires 1 Great Plains 1 Historia 1 Historical geography 1 Historiography 1 Indian painting 1 Indian philosophy 1 Indiens d'Amérique 1 Influence 1 Labor camps 1 Land tenure 1 Magic 1 Methodology 1 Méthodologie 1 Migrant agricultural laborers 1 Migrant agricultural laborers in art 1 Missions 1 New Deal, 1933-1939 1 Oglala philosophy 1 Outils de pierre 1 Outils préhistoriques 1 Peintures rupestres 1 Personal narratives 1 Petroglyphs 1 Pétroglyphes 1 Photograph collections 1 Pioneers 1 Prairie ecology 1 Prairies 1 Prevention and control 1 Rites and ceremonies 1 Rock paintings 1 Rural conditions 1 Santee Indians 1 Social history 1 Social life and customs 1 Stofstormen 1 Stone implements 1 Sun dance 1 Tempestades de polvo 1 Territorial expansion 1 Teton Indians 1 Time travel 1 Tree houses 1 Warfare 1 Wars, 1876 1