Subject
- Douglas fir10
- Forest fires -- Prevention and control9
- Forests and forestry -- Measurement7
- Lumber trade -- Northwest, Pacific5
- Douglas fir -- Pruning4
- Forest management4
- Logging4
- Wood waste -- Recycling4
- Aeronautics in forest fire control3
- Building, Wooden3
- Forest fires -- Oregon -- Prevention and control3
- Log transportation3
- Logging -- Northwest, Pacific3
- Lumber trade3
- Oregon and California Railroad3
- Plant hormones3
- Plywood3
- Ponderosa pine3
- Aerial photogrammetry2
- Aeronautics in forestry2