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- Izaak Walton League of America 7
- Rivers--Oregon 7
- Water--Pollution 5
- Dams 3
- Birds--Conservation 2
- Dams--Design and construction 1
- Fishes--Conservation 1
- Forests and forestry 1
- Hunting 1
- Inland water transportation 1
- Lectures and lecturing 1
- Oregon Audubon Society 1
- Parks 1
- Salmon 1
- Sewage disposal plants 1
- Wildlife conservation 1
- Wildlife refuges 1
- sardine 1