| North Western Electric | Portland | OR |
| Northwest Marine & Iron Shipyard | Portland | OR |
| Northwest Natural Gas | Corvallis | OR |
| Northwest Natural Gas | Salem | OR |
| Norwalk Victory | Portland | OR |
| Norway Victory | Portland | OR |
| Novise | Portland | OR |
| Novorossick | Portland | OR |
| N. P. West Side Team Track | Portland | OR |
| Nyssa Sugar Factory | Nyssa | OR |
| Oak Hills School | Beaverton | OR |
| Ocean Navigator | Portland | OR |
| Oceanside Lumber | Garibaldi | OR |
| Ochoco | Portland | OR |
| Ochoco Lumber | Prineville | OR |
| Ogden Sacramento | Portland | OR |
| Oglethorpe Victory | Portland | OR |
| Oilfield | Portland | OR |
| Oki Nursery | Aurora | OR |
| Olds Wortman & King Building | Portland | OR |
| Oleum | Portland | OR |
| Olga Coal | Portland | OR |
| Oliver Wendell Holmes | Portland | OR |
| Oliver W. Holmes | Portland | OR |
| Olson-Lawyer Lumber | Medford | OR |
| Olympic Challenger | Portland | OR |
| Olympic Manufacturing | Gresham | OR |
| Omark Industries | Portland | OR |
| Omnium Wanderer | Portland | OR |
| Opticraft Central Building | Portland | OR |
| Orcher | Portland | OR |
| Oregan State T.B. Hospital | Salem | OR |
| Oregon | Portland | OR |
| Oregonian Building | Portland | OR |
| Oregonian Publishing | Portland | OR |
| Oregon Laundry & Dry Cleaners | Portland | OR |
| Oregon Linen Rental | Portland | OR |
| Oregon Metallurgical | Albany | OR |
| Oregon National Bank | Portland | OR |
| Oregon Portland Cement | Lake Oswego | OR |
| Oregon Portland Cement | Lime | OR |
| Oregon Pulp & Paper | Salem | OR |
| Oregon Railroad & Navigation | The Dalles | OR |
| Oregon Railroad & Navigation | Wyeth | OR |
| Oregon Shipbuilding Corporation | Portland | OR |
| Oregon Standard | Portland | OR |
| Oregon State Board Of Control | Klamath Falls | OR |
| Oregon State Hospital | Salem | OR |
| Oregon State Insane Asylum | Salem | OR |
| Oregon State Penitentiary | Salem | OR |
