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- Rivers--Oregon 38
- Dams 17
- Fishways 8
- Forests and forestry 6
- Salmon 6
- Power-plants 4
- Geology--Oregon 3
- Hydroelectric power plants 2
- Lampreys 2
- Waterfalls 2
- Bridges 1
- Fish habitat improvement 1
- Fish hatcheries 1
- Fishes--Conservation 1
- Flood control 1
- Flumes 1
- Footbridges 1
- Government publications 1
- Lakes 1
- Mountains--Oregon 1