Topic
- Agriculture 5
- Beavers 5
- Lakes--Oregon 5
- Conservation of natural resources 4
- Conservation--Law and legislation 4
- Fishways 4
- Irrigation 4
- Fisheries 3
- Geese 3
- National parks and reserves 3
- Nature photography 3
- Oregon Audubon Society 3
- Pacific College (Newberg, Or.) 3
- Waterfowl 3
- Antelopes 2
- Bighorn sheep 2
- Birds--Housing 2
- Chipmunks 2
- Coots 2
- Degrees, Academic 2