Subject
Minnesota Description and travel
29
Minnesota
10
Minnesota History
8
Water quality
8
Indians of North America
7
Frontier and pioneer life
6
Dakota Indians
5
Groundwater Pollution
5
Stream measurements
5
Drill cores
4
Geology
4
Groundwater Quality
4
Hydrology
4
Minnesota Antiquities
4
Water resources development
4
Agricultural colonies
3
Aquifers
3
Borings
3
Catholics
3
Dakota Territory Description and travel
3
Forest ecology
3
Geochemical prospecting
3
Hubbard County (Minn.) Climate
3
Hydrology Research
3
Indians of North America Wars
3
Minnesota Economic conditions
3
Ojibwa Indians
3
United States Discovery and exploration
3
Voyageurs National Park (Minn.)
3
Water Pollution
3
Agricultural chemicals Environmental aspects
2
Agricultural credit
2
Agricultural subsidies
2
Agriculture
2
Bank robberies
2
Drill core analysis
2
Freshwater ecology
2
Geochemistry
2
Geomagnetism
2
Grand Portage National Monument (Minn.)
2
Gravity anomalies
2
Groundwater flow
2
Lakes
2
Land titles Registration and transfer
2
Mercury Environmental aspects
2
Mines and mineral resources
2
Minnesota Politics and government
2
Minnesota River (S.D. and Minn.)
2
Mississippi River Description and travel
2
National monuments Management
2
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