Topics
Climate
25
Climatology
24
Archaeological surveying
14
Antiquities
13
Geology
5
Hydroelectric power plants
5
Economic aspects
3
Economic conditions
3
Environmental aspects
3
Historic sites
3
Hydrology
3
Measurement
3
Alaska Natives
2
Dams
2
Economic history
2
Excavations (Archaeology)
2
Freezes (Meteorology)
2
Ice
2
Ice on rivers, lakes, etc
2
Indians of North America
2
Regional economics
2
Social aspects
2
Social conditions
2
Air quality
1
Animals
1
Archaeological geology
1
Bird surveys
1
Birds of prey
1
Cultural property
1
Data processing
1
Design and construction
1
Ecology
1
Economic surveys
1
Environmental conditions
1
Ethnology
1
Fishes
1
Geographic information systems
1
Geological surveys
1
Licenses
1
Methodology
1
Municipal services
1
Paleontological excavations
1
Particles
1
Peregrine falcon
1
Power utilization
1
Roads
1
Soil surveys
1
Soils
1
Telephone surveys
1