Forest management 34 Northwest, Pacific 34 Earthquake hazard analysis 26 Northwest, Pacific History 24 Indians of North America 22 Northwest, Pacific Description and travel 20 Forests and forestry 17 Geology 17 Forest policy 16 Earthquakes 14 Forest reserves 10 Mines and mineral resources 10 Predatory marine animals Control Law and legislation 10 Sea lions Control Law and legislation 10 Water resources development 10 Endangered species 9 Geology, Structural 9 Spotted owl 9 Fishes Conservation 8 Forest reserves Management 8 Geology, Stratigraphic 8 Groundwater 8 Old growth forests 8 Pacific salmon Predators of Control 8 Ecosystem management 7 Electric utilities 7 Forest conservation 7 Forest ecology 7 National parks and reserves 7 Pacific salmon fisheries 7 Seismology 7 Wildlife conservation 7 Electric utilities Law and legislation 6 Forest management Environmental aspects 6 Oregon 6 Oregon Description and travel 6 Oregon Territory History 6 Paleontology 6 Reforestation 6 Subduction zones 6 Earthquake engineering 5 Fish habitat improvement 5 Fishery management 5 Floods 5 Forest products industry 5 Forests and forestry Economic aspects 5 Frontier and pioneer life 5 Fur trade 5 Management 5 Northwest Coast of North America 5 Old growth forest conservation 5 Power resources 5 Public lands Management 5 Salmon 5 Sustainable forestry 5 Water quality 5 Biodiversity conservation 4 Birds 4 Climatic changes 4 Earthquake prediction 4 Earthquakes Computer simulation 4 Fisheries subsidies 4 Forest reserves Recreational use 4 Forests and forestry Research 4 Habitat conservation 4 Hydroelectric power plants Environmental aspects 4 Ice Age Floods National Geologic Trail 4 Ore deposits 4 Overland journeys to the Pacific 4 Railroads 4 Salmon Spawning 4 Trails Law and legislation 4 Trees Diseases and pests 4 Water-supply 4 Anadromous fishes 3 Appropriations and expenditures 3 Bird populations 3 Columbia River Power utilization 3 Douglas fir Prices 3 Economic development 3 Emergency management 3 Endangered species Law and legislation 3 Fishery law and legislation 3 Forest monitoring 3 Forest plants 3 Forest protection 3 Geomorphology 3 Glacial epoch 3 Gravity anomalies 3 Hydroelectric power plants 3 Idaho 3 Indians of North America Folklore 3 Indians of North America Government relations 3 Invasive plants Control 3 Invasive plants Environmental aspects 3 Irrigation laws 3 Lumber trade 3 Missions 3 Missoula, Lake 3 National parks and reserves Law and legislation 3