| Corvallis Clinic | Corvallis | OR |
| Corvallis Junior High School | Corvallis | OR |
| Cosmopolitan Motor Hotel | Portland | OR |
| Coulee Dam | Portland | OR |
| Council Crest | Portland | OR |
| Council Great | Portland | OR |
| Court House | Salem | OR |
| Coxcomb Hill | Portland | OR |
| Cranston Victory | Portland | OR |
| Crater Lake | Portland | OR |
| Creighton Victory | Portland | OR |
| Crown Columbia Pulp & Paper | Portland | OR |
| Crown Plaza | Portland | OR |
| Crown Willamette Paper | West Linn | OR |
| Crown Willamette Paper | Lebanon | OR |
| Crown Zellerbach | Portland | OR |
| Crown Zellerbach | Clatskanie | OR |
| Crown Zellerbach | Lebanon | OR |
| Crown Zellerbach | Wauna | OR |
| Crown Zellerbach | West Linn | OR |
| Curtis Woods | Portland | OR |
| Custom Plywood | Grants Pass | OR |
| Czechoslovakia Victory | Portland | OR |
| Dairy Cooperative Association | Portland | OR |
| Dale Pense | Salem | OR |
| Dammasch State Hospital | Wilsonville | OR |
| Daniel H. Lownsdale | Portland | OR |
| Daniel S Lamont | Portland | OR |
| Darling Ingredients | Portland | OR |
| Dartmouth Victory | Portland | OR |
| David B Henderson | Portland | OR |
| David E. Day | Portland | OR |
| Davis Office Building | Portland | OR |
| Daw Forest Products | Bend | OR |
| Dekabrist | Portland | OR |
| Delazon Smith | Portland | OR |
| Delta Electric | Portland | OR |
| Delta Industries | Portland | OR |
| Denebola | Portland | OR |
| Derks Building | Portland | OR |
| Dewitt Clinton | Portland | OR |
| Diamond Fruit | Odell | OR |
| Diddo | Portland | OR |
| Dierks Building | Portland | OR |
| Dillingham Shipbuilding | Portland | OR |
| Diodato | Portland | OR |
| D.M. Gibson | Portland | OR |
| Doernbecher Manufacturing | Portland | OR |
| Dollar-A-Day Car Rental | Portland | OR |
| Domestic Laundry | Pendleton | OR |
