Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Cinder Cone | Summit | 1654 | Wasco | 44 50 23 N | 121 44 43 W |
| Cinder Hill | Summit | 1952 | Deschutes | 43 45 02 N | 121 08 55 W |
| Cinder Hill Recreation Site | Locale | 1951 | Deschutes | 43 44 04 N | 121 11 43 W |
| Cinder Prairie | Area | 1629 | Douglas | 43 20 54 N | 122 25 24 W |
| Cinder Prairie Lookout | Locale | 1633 | Douglas | 43 20 53 N | 122 25 33 W |
| Cinder Prairie Way | Trail | 1292 | Douglas | 43 20 41 N | 122 26 45 W |
| Cinderella Mine (historical) | Mine | 1263 | Linn | 44 13 52 N | 122 20 03 W |
| Cinderella Spring | Spring | 1270 | Douglas | 43 14 21 N | 122 40 28 W |
| Cindy Creek | Stream | | Douglas | 42 43 54 N | 123 24 29 W |
| Cinge Creek | Stream | | Lane | 43 35 34 N | 122 42 03 W |
| Cinnabar Creek | Stream | | Lane | 43 33 14 N | 123 03 52 W |
| Cinnabar Flat | Flat | 1483 | Grant | 44 11 44 N | 119 33 59 W |
| Cinnabar Gap | Gap | 1378 | Jackson | 42 06 49 N | 122 50 24 W |
| Cinnabar Gulch | Valley | | Jackson | 42 06 42 N | 122 49 26 W |
| Cinnabar Lookout | Locale | 1128 | Jackson | 42 07 54 N | 123 00 20 W |
| Cinnabar Mine | Mine | 1696 | Grant | 44 21 08 N | 119 09 25 W |
| Cinnabar Mountain | Summit | 1869 | Grant | 44 20 50 N | 119 09 05 W |
| Cinnabar Mountain | Summit | 754 | Jackson | 42 34 24 N | 122 56 04 W |
| Cinnabar Mountain | Summit | 1190 | Jackson | 42 07 54 N | 123 00 25 W |
| Cinnabar Mountain | Summit | 750 | Lane | 43 32 38 N | 123 03 39 W |
| Cinnabar Mountain Mine | Mine | 708 | Jackson | 42 34 23 N | 122 55 54 W |
| Cinnamon Butte | Summit | 1882 | Douglas | 43 14 27 N | 122 06 44 W |
| Cinnamon Hills City Park | Park | 83 | Washington | 45 21 08 N | 122 50 18 W |
| Cinnamon Peak | Summit | 1933 | Klamath | 42 45 49 N | 122 16 21 W |
| Cipole (historical) | Locale | 48 | Washington | 45 22 28 N | 122 48 42 W |
| Cipole School | School | 41 | Washington | 45 22 41 N | 122 48 52 W |
| Circle Bar | Locale | 1184 | Harney | 43 21 37 N | 118 26 51 W |
| Circle Bar Golf Club | Locale | 460 | Lane | 43 45 28 N | 122 27 14 W |
| Circle Bar Ranch | Locale | 1190 | Harney | 43 21 39 N | 118 27 43 W |
| Circle Bar Ranch | Locale | 1483 | Malheur | 42 31 37 N | 117 02 22 W |
| Circle Bar Ranch | Locale | 1170 | Morrow | 45 01 31 N | 119 26 09 W |
| Circle Bar Spring | Spring | 1165 | Morrow | 45 01 38 N | 119 26 03 W |
| Circle Butte | Summit | 1700 | Malheur | 44 11 20 N | 117 48 04 W |
| Circle Creek | Stream | | Clatsop | 45 58 13 N | 123 55 49 W |
| Circle Lake | Lake | 1421 | Jefferson | 44 24 44 N | 121 49 39 W |
| Circle M Ranch | Locale | 879 | Jefferson | 44 29 30 N | 121 39 05 W |
| Circle W Ranch-Condon Airstrip | Airport | 594 | Gilliam | 45 25 39 N | 120 03 14 W |
| City Creek | Stream | | Lane | 43 48 04 N | 123 05 51 W |
| City Creek | Stream | | Lane | 43 29 59 N | 122 35 54 W |
| City Creek Shelter | Locale | 573 | Lane | 43 29 51 N | 122 36 00 W |
| City Farm | Locale | 712 | Gilliam | 45 17 49 N | 120 14 30 W |
| City Gulch | Valley | | Jackson | 41 59 57 N | 123 01 56 W |
| City Gulch | Valley | | Malheur | 44 25 31 N | 117 35 29 W |
| City Gulch | Valley | | Malheur | 44 21 58 N | 117 36 35 W |
| City Limits (historical) | Locale | 10 | Multnomah | 45 32 45 N | 122 42 14 W |
| City of Medford Watershed | Area | 1101 | Jackson | 42 28 44 N | 122 23 14 W |
| City of Portland Number 1 Dam | Dam | 124 | Multnomah | 45 30 29 N | 122 35 34 W |
| City of Portland Number 3 Dam | Dam | 88 | Multnomah | 45 31 11 N | 122 42 10 W |
| City of Portland Number 4 Dam | Dam | 78 | Multnomah | 45 31 05 N | 122 42 10 W |
| City of Portland Number 5 Dam | Dam | 124 | Multnomah | 45 30 41 N | 122 35 52 W |
| City of Portland Number 6 Dam | Dam | 89 | Multnomah | 45 30 41 N | 122 36 04 W |
| City of Portland Reservoir Number 1 | Reservoir | 124 | Multnomah | 45 30 29 N | 122 35 34 W |
| City of Portland Reservoir Number 3 | Reservoir | 88 | Multnomah | 45 31 11 N | 122 42 10 W |
| City of Portland Reservoir Number 4 | Reservoir | 78 | Multnomah | 45 31 05 N | 122 42 10 W |
| City of Portland Reservoir Number 5 | Reservoir | 124 | Multnomah | 45 30 41 N | 122 35 52 W |
| City of Portland Reservoir Number 6 | Reservoir | 89 | Multnomah | 45 30 41 N | 122 36 04 W |
| City of Roseburg Sewage Disposal Plant | Locale | 129 | Douglas | 43 12 34 N | 123 23 47 W |
| City of Toledo Watershed | Area | 158 | Lincoln | 44 33 14 N | 123 54 34 W |
| City Park | Park | 24 | Coos | 43 06 47 N | 124 25 39 W |
| City Park | Park | 591 | Morrow | 45 21 26 N | 119 33 09 W |
| City Park | Park | 63 | Washington | 45 29 01 N | 122 48 25 W |
| City Pocket Park | Park | 814 | Wallowa | 45 33 54 N | 117 54 59 W |
| City View Cemetery | Cemetery | 111 | Marion | 44 55 09 N | 123 03 04 W |
| City View Reservoir | Reservoir | 243 | Lane | 44 01 45 N | 123 07 57 W |
| City-County Airport | Airport | 744 | Jefferson | 44 39 59 N | 121 08 49 W |
| Civic Pride Park | Park | 27 | Columbia | 45 51 39 N | 122 48 32 W |
| Civil Bend | Bend | 271 | Douglas | 43 06 39 N | 123 29 04 W |
| Civil Bend (historical) | Populated Place | 159 | Douglas | 43 06 24 N | 123 25 29 W |
| Civil Bend Cemetery | Cemetery | 172 | Douglas | 43 07 04 N | 123 25 03 W |
| Civil Bend Post Office (historical) | Post Office | 159 | Douglas | 43 06 24 N | 123 25 29 W |
| Clabber Creek | Stream | | Douglas | 43 46 18 N | 123 35 06 W |
| Clackamas | Populated Place | 50 | Clackamas | 45 24 27 N | 122 34 13 W |
| Clackamas Cemetery | Cemetery | 31 | Clackamas | 45 25 29 N | 122 34 34 W |
| Clackamas Community College | School | 129 | Clackamas | 45 19 29 N | 122 34 29 W |
| Clackamas County | Civil | 614 | Clackamas | 45 14 58 N | 122 10 04 W |
| Clackamas County Fairgrounds | Locale | 45 | Clackamas | 45 16 16 N | 122 41 19 W |
| Clackamas County Redsoils Airstrip | Airport | 137 | Clackamas | 45 20 05 N | 122 35 49 W |
| Clackamas Heights | Populated Place | 39 | Clackamas | 45 22 16 N | 122 34 45 W |
| Clackamas Heights Airstrip | Airport | 149 | Clackamas | 45 21 59 N | 122 33 04 W |
| Clackamas High School | School | 35 | Clackamas | 45 25 23 N | 122 35 38 W |
| Clackamas Lake | Lake | 1018 | Clackamas | 45 05 46 N | 121 44 34 W |
| Clackamas Lake Recreation Site | Locale | 1023 | Clackamas | 45 05 44 N | 121 44 54 W |
| Clackamas Post Office | Post Office | 50 | Clackamas | 45 24 27 N | 122 34 13 W |
| Clackamas Rapids | Rapids | 4 | Clackamas | 45 22 16 N | 122 36 44 W |
| Clackamas River | Stream | | Clackamas | 45 22 21 N | 122 36 31 W |
| Clackamas River Ranger Station | Building | 134 | Clackamas | 45 17 41 N | 122 20 37 W |
| Clackamas River Scenic Waterway | Park | 31 | Clackamas | 45 23 30 N | 122 28 36 W |
| Clackamas School | School | 32 | Clackamas | 45 25 29 N | 122 34 09 W |
| Clackamette Cove | Bay | 4 | Clackamas | 45 22 21 N | 122 35 54 W |
| Clackamette Park | Park | 7 | Clackamas | 45 22 14 N | 122 36 14 W |
| Clackemas Post Office (historical) | Post Office | 42 | Clackamas | 45 22 59 N | 122 27 04 W |
| Claggett Cemetery | Cemetery | 56 | Marion | 45 00 54 N | 123 01 42 W |
| Claggett Creek | Stream | | Marion | 45 01 43 N | 123 01 49 W |
| Claggett Creek Park | Park | 41 | Marion | 44 59 46 N | 123 01 11 W |
| Claggett Lake | Lake | 1499 | Marion | 44 45 24 N | 121 52 30 W |
| Claire Prairie | Area | 1550 | Lane | 43 49 14 N | 122 07 49 W |
| Clammer Creek | Stream | | Tillamook | 45 41 09 N | 123 43 44 W |
| Clapboard Gulch | Valley | | Josephine | 42 11 29 N | 123 16 24 W |
| Clapp Meadow | Flat | 1416 | Baker | 44 56 34 N | 118 05 32 W |
| Clapper Creek | Stream | | Lane | 44 08 49 N | 122 21 54 W |
| Clara Brownell Middle School | School | 101 | Umatilla | 45 55 00 N | 119 20 18 W |
| Clara Spring | Spring | 1115 | Malheur | 44 07 15 N | 117 31 44 W |
| Claremont (historical) | Locale | 12 | Multnomah | 45 35 04 N | 122 46 05 W |
| Claremont Cemetery | Cemetery | 123 | Polk | 44 43 23 N | 123 30 54 W |
| Clarence Creek | Stream | | Tillamook | 45 15 02 N | 123 38 28 W |
| Clarenoon School | School | 30 | Multnomah | 45 35 24 N | 122 43 24 W |
| Clarion Post Office (historical) | Post Office | 270 | Multnomah | 45 34 51 N | 122 48 03 W |
| Clark Branch | Stream | | Douglas | 43 04 35 N | 123 22 01 W |
| Clark Brook | Stream | | Lane | 44 09 14 N | 122 54 34 W |
| Clark Butte | Summit | 809 | Lane | 43 59 22 N | 122 34 31 W |