Topics
Climate
38
Climatology
30
Archaeological surveying
14
Antiquities
13
Environmental aspects
7
Hydroelectric power plants
7
Hydrology
7
Ice on rivers, lakes, etc
7
Ice mechanics
5
Temperature
5
Dams
4
Economic conditions
4
Geology
4
Economic aspects
3
Historic sites
3
Measurement
3
Social conditions
3
Stream measurements
3
Alaska Natives
2
Economic history
2
Excavations (Archaeology)
2
Freezes (Meteorology)
2
Ice
2
Indians of North America
2
Regional economics
2
Social aspects
2
Air quality
1
Animals
1
Archaeological geology
1
Bird surveys
1
Birds of prey
1
Cultural property
1
Design and construction
1
Ecology
1
Economic surveys
1
Environmental conditions
1
Ethnology
1
Fishes
1
Geological surveys
1
Licenses
1
Meteorology
1
Methodology
1
Municipal services
1
Observations
1
Paleontological excavations
1
Particles
1
Peregrine falcon
1
Research
1
Roads
1
Soil surveys
1
more ...