Environment and Natural Resources
- Anti-Nuclear Movement
- Applegate River
- Elmer Ivan Applegate (1867-1949)
- Chester H. Armstrong (1892-1973)
- Ashland
- Athapaskan Indians
- Les AuCoin (1942-)
- Autzen House
- Simon Benson (1851-1942)
- Bowpickers
- Camas
- Cascade Locks
- Classical Chinese Garden
- John Colter (ca. 1775-1813)
- Columbia River Bar Pilots
- Columbia River Fisherman's Protective Union
- Columbia River Inter-Tribal Fish Commission
- Columbia River Packers Association
- Conifers
- Coos Bay
- Crater Lake National Park
- Crooked River
- Crooked River Project
- William Cusick (1842-1922)
- Deschutes Land Trust
- Douglas fir
- William O. Douglas (1898-1980)
- Echo
- Eight Dollar Mountain
- Engelmann Spruce
- Estacada
- Evans Products Company
- Flax and Linen Industry of Oregon
- French Prairie
- Ghost Towns of the Illinois River Valley
- Helen Gilkey (1886-1972)
- Zane Grey (1872–1939)
- Guild's Lake
- Henry Haefner (1884-1978)
- Carl Hall (1921-1996)
- Harry & David/Bear Creek Orchards
- Childe Hassam (1859 - 1935)
- Louis F. Henderson (1853-1942)
- Heppner flood of 1903
- Greg Higgins (1958-)
- James J. Hill (1838-1916)
- Thomas Howell (1842-1912)
- Robert Deniston Hume (1845-1908)
- Hutson Museum
- Illinois Valley Soil & Water Conservation District
- Glenn Jackson (1902-1980)
- John Jeffrey (1828-?)
- Juniper
- Kinzua (town)
- Klamath River
- Lake Oswego
- Land Use Planning
- Lilla Leach (1886-1980)
- Lithia Park
- Long Creek (town)
- Lorane (town)
- Lower Klamath Lake
- Etienne Lucier (1793-1853)
- Macleay Park
- Malin
- Marionberry
- David T. Mason (1883-1973)
- Georgia Mason (1910-2007)
- McKenzie River
- John C. Merriam (1869-1945)
- Thomas Leander Moorhouse (1850-1926)
- Wayne Morse (1900-1974)
- Mt. Hood Freeway
- Mt. Tabor Park
- Thornton Munger (1883-1975)
- Myrtlewood
- Myrtlewood Industry
- National Reclamation Act (1902)
- Richard Neuberger (1912-1960)
- Noble fir
- Oaks Bottom
- Peter Skene Ogden (1790-1854)
- Olmsted Portland Park Plan
- Oregon Chub
- Walter Perry (1873-1959)
- Port Orford Cedar
- Portland Park Blocks
- Roseburg Forest Products
- Alexander Ross (1782-1856)
- Salal
- Seine Fishing
- Senate Bill 100
- Sheridan
- C.A. Smith Lumber Company
- David Sohappy (1925-1991)
- SOLV
- South Slough National Estuarine Research Reserve
- Albert Sweetser (1861-1940)
- David Thompson (1770-1857)
- Three Sisters Wilderness
- Tillamook Burn
- Tree Sitters
- U.S. Army Corps of Engineers
- U.S. Fish and Wildlife Forensics Lab
- Umpqua River
- Vanport
- Waldo (city)
- John B.Waldo (1844-1907)
- C. B. Watson (1849-1930)
- Western hemlock
- Willamette Industries
- Willamette River
- Willamina (city)
- John Yeon (1910-1994)
