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- Rivers--Oregon 423
- Dams 163
- Waterfalls 69
- Fishways 53
- Salmon 22
- Hydroelectric power plants 18
- Rivers--Washington (State) 17
- Canals 16
- Sawmills 16
- Power-plants 13
- Lakes 10
- Boats 9
- Forests and forestry 9
- Rapids 9
- Coarse woody debris 7
- Fish hatcheries 7
- Lumber trade 7
- Salmon--Artificial spawning 6
- Fish screens 5
- Logging--Machinery 5