Topics
Recreational use
Wilderness areas
8
Rivers
6
Recreational surveys
5
Research
5
Aesthetic resources
3
Dams
3
Hydroelectric power plants
3
Archaeological significance
2
Economic aspects
2
Power utilization
2
Social aspects
2
Environmental aspects
1
Landscape protection
1
Light pollution
1
Noise pollution
1
Outdoor recreation
1
Trails
1