Subject
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Mines and mineral resources
3
Natural areas
3
Nutrients
3
Otters
3
Pipelines
3
Planting
3
Plants, Fossil
3
Pollution
3
Ponies
3
Power plants
3
Problem bears
3
Research
3
Roads
3
Sedimentation
3
Shore birds
3
Spruce
3
Standards
3
Streams
3
Synthetic fuels
3
Timber
3
Turbines
3
Water conservation
3
Water management
3
Wood fuels
3
Agate
2
Air quality
2
Airphoto interpretation
2
Alger, Francis, 1807-1863
2
Archaeology
2
Ash
2
Beach erosion
2
Biological control
2
Botany
2
Boundaries
2
Brown spruce longhorn beetle
2
Calcium carbonate
2
Canals
2
Canker-worms
2
Cement materials
2
Classification
2
Coal deposits
2
Coal seams
2
Coalbed methane
2
Collecting
2
Community histories
2
Companies
2
Concrete
2
Design and construction
2
Ducks
2
Dutch elm disease
2
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