Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| South Fork Rock Creek | Stream | | Gilliam | 45 19 10 N | 120 03 51 W |
| South Fork Rock Creek | Stream | | Lane | 43 39 34 N | 122 57 53 W |
| South Fork Rocky Gulch | Valley | | Josephine | 42 34 36 N | 123 35 59 W |
| South Fork Rogue River | Stream | | Jackson | 42 42 41 N | 122 32 48 W |
| South Fork Rough and Ready Creek | Stream | | Josephine | 42 05 17 N | 123 45 42 W |
| South Fork Round Prairie Creek | Stream | | Josephine | 42 22 44 N | 123 29 52 W |
| South Fork Ruby Creek | Stream | | Grant | 44 46 48 N | 118 29 47 W |
| South Fork Ryegrass Creek | Stream | | Malheur | 42 59 20 N | 118 04 04 W |
| South Fork Salmon River | Stream | | Clackamas | 45 16 19 N | 121 56 18 W |
| South Fork Salmonberry Creek | Stream | | Benton | 44 19 57 N | 123 41 01 W |
| South Fork Salmonberry River | Stream | | Tillamook | 45 42 50 N | 123 32 48 W |
| South Fork Salt Creek | Stream | | Lane | 43 39 21 N | 122 13 37 W |
| South Fork Schooner Creek | Stream | | Lincoln | 44 57 16 N | 123 54 42 W |
| South Fork Scott Creek | Stream | | Linn | 44 31 32 N | 122 42 20 W |
| South Fork Seekseequa Creek | Stream | | Jefferson | 44 41 15 N | 121 22 24 W |
| South Fork Shale Creek | Stream | | Coos | 42 42 41 N | 124 03 17 W |
| South Fork Shelter | Locale | 554 | Lane | 43 51 21 N | 122 33 09 W |
| South Fork Siletz River | Stream | | Polk | 44 52 48 N | 123 42 40 W |
| South Fork Silver Creek | Stream | | Josephine | 42 27 08 N | 123 52 44 W |
| South Fork Silver Creek | Stream | | Marion | 44 53 21 N | 122 39 48 W |
| South Fork Simpson Creek | Stream | | Lane | 43 31 30 N | 122 19 29 W |
| South Fork Siuslaw River | Stream | | Lane | 43 49 21 N | 123 15 41 W |
| South Fork Sixes River | Stream | | Curry | 42 48 15 N | 124 18 22 W |
| South Fork Smith River | Stream | | Douglas | 43 46 55 N | 123 28 11 W |
| South Fork Snyder Creek | Stream | | Lake | 42 30 05 N | 120 07 14 W |
| South Fork Spencer Creek | Stream | | Lane | 43 59 24 N | 123 09 34 W |
| South Fork Spencer Creek | Stream | | Lincoln | 44 43 56 N | 124 02 09 W |
| South Fork Sprague River | Stream | | Klamath | 42 26 18 N | 121 06 30 W |
| South Fork Spring | Spring | 1397 | Klamath | 42 56 57 N | 121 32 15 W |
| South Fork Spring Creek | Stream | | Baker | 44 57 20 N | 117 15 52 W |
| South Fork Spring Creek | Stream | | Jefferson | 44 34 42 N | 121 30 21 W |
| South Fork Spring Creek | Stream | | Union | 45 20 43 N | 118 18 05 W |
| South Fork Spruce Run Creek | Stream | | Clatsop | 45 48 40 N | 123 35 11 W |
| South Fork Squaw Creek | Stream | | Malheur | 43 44 37 N | 117 42 32 W |
| South Fork Squaw Creek | Stream | | Wallowa | 45 22 02 N | 116 52 46 W |
| South Fork Staley Creek | Stream | | Douglas | 43 23 38 N | 122 19 06 W |
| South Fork Steelhead Creek | Stream | | Douglas | 43 23 34 N | 122 39 06 W |
| South Fork Stell Creek | Stream | | Lane | 43 37 28 N | 122 55 08 W |
| South Fork Street Creek | Stream | | Jefferson | 44 35 07 N | 121 31 10 W |
| South Fork Summit Creek | Stream | | Wallowa | 45 47 39 N | 116 56 49 W |
| South Fork Sweet Creek | Stream | | Lane | 43 56 37 N | 123 51 12 W |
| South Fork Sycan River | Stream | | Lake | 42 39 48 N | 120 47 39 W |
| South Fork Taylor Creek | Stream | | Josephine | 42 29 59 N | 123 39 07 W |
| South Fork Teal Creek | Stream | | Polk | 44 50 17 N | 123 29 03 W |
| South Fork Tenmile Creek | Stream | | Lane | 44 12 47 N | 123 58 25 W |
| South Fork Tickle Creek | Stream | | Clackamas | 45 24 19 N | 122 19 49 W |
| South Fork Timber Company (historical) | Locale | 193 | Tillamook | 45 42 45 N | 123 32 18 W |
| South Fork Toppin Creek | Stream | | Malheur | 42 13 08 N | 117 06 49 W |
| South Fork Trail | Trail | 754 | Douglas | 42 49 43 N | 123 23 04 W |
| South Fork Trail | Trail | 1425 | Klamath | 42 34 09 N | 122 16 43 W |
| South Fork Trask River | Stream | | Tillamook | 45 26 24 N | 123 36 39 W |
| South Fork Trimble Creek | Stream | | Jackson | 42 29 56 N | 123 09 29 W |
| South Fork Trout Creek | Stream | | Crook | 44 04 60 N | 119 48 36 W |
| South Fork Trout Creek | Stream | | Crook | 44 03 46 N | 119 44 26 W |
| South Fork Trout Creek | Stream | | Harney | 43 52 15 N | 118 53 40 W |
| South Fork Trout Creek | Stream | | Klamath | 42 29 16 N | 121 37 03 W |
| South Fork Tumalo Creek | Stream | | Deschutes | 44 01 46 N | 121 33 25 W |
| South Fork Umatilla River | Stream | | Umatilla | 45 43 32 N | 118 11 18 W |
| South Fork Valentine Creek | Stream | | Marion | 44 48 33 N | 122 41 27 W |
| South Fork Vance Creek | Stream | | Grant | 44 17 18 N | 118 58 44 W |
| South Fork Vine Maple Creek | Stream | | Jackson | 42 38 18 N | 122 28 21 W |
| South Fork Visher Creek | Stream | | Malheur | 43 26 09 N | 118 10 32 W |
| South Fork Wade Creek | Stream | | Clackamas | 45 17 19 N | 122 18 24 W |
| South Fork Walla Walla River | Stream | | Umatilla | 45 53 53 N | 118 18 27 W |
| South Fork Wallowa Creek | Stream | | Jackson | 42 42 07 N | 122 19 11 W |
| South Fork Warm Springs River | Stream | | Wasco | 44 58 03 N | 121 35 07 W |
| South Fork Water Board Intake | Locale | 203 | Clackamas | 45 11 57 N | 122 13 34 W |
| South Fork Waterhole | Lake | 1273 | Harney | 43 08 60 N | 118 19 34 W |
| South Fork Way | Trail | 1122 | Lane | 43 57 33 N | 121 57 28 W |
| South Fork Weist Creek | Stream | | Lincoln | 44 23 46 N | 124 01 23 W |
| South Fork Wenaha River | Stream | | Wallowa | 45 57 03 N | 117 47 39 W |
| South Fork West Camp Creek | Stream | | Baker | 44 19 60 N | 118 12 48 W |
| South Fork Whalehead Creek | Stream | | Curry | 42 08 54 N | 124 20 44 W |
| South Fork Whisky Creek | Stream | | Wallowa | 45 35 59 N | 117 26 02 W |
| South Fork Whychus Creek | Stream | | Deschutes | 44 09 11 N | 121 40 57 W |
| South Fork Wilkins Creek | Stream | | Umatilla | 45 07 26 N | 119 00 37 W |
| South Fork Willow Creek | Stream | | Harney | 42 08 55 N | 118 41 09 W |
| South Fork Willow Creek (historical) | Stream | | Union | 45 28 03 N | 118 00 28 W |
| South Fork Wilson River | Stream | | Tillamook | 45 36 22 N | 123 27 46 W |
| South Fork Winberry Creek | Stream | | Lane | 43 54 00 N | 122 37 10 W |
| South Fork Wind Creek | Stream | | Douglas | 43 38 54 N | 124 05 49 W |
| South Fork Wind Creek | Stream | | Grant | 44 14 45 N | 119 36 59 W |
| South Fork Youngs River | Stream | | Clatsop | 46 00 11 N | 123 40 41 W |
| South Forks Falls Creek | Stream | | Clackamas | 44 57 29 N | 122 31 14 W |
| South Fox Reservoir | Reservoir | 1472 | Crook | 44 15 49 N | 120 11 27 W |
| South Gawley Ridge | Ridge | 1107 | Clackamas | 44 54 34 N | 122 24 54 W |
| South Grade Reservoir | Reservoir | 1494 | Klamath | 42 33 57 N | 121 33 09 W |
| South Green Mountain | Summit | 1480 | Lake | 43 21 30 N | 120 42 44 W |
| South Gregory Creek Reservoir | Reservoir | 1366 | Malheur | 43 56 49 N | 117 55 13 W |
| South Guzzler Waterhole | Reservoir | 1145 | Baker | 44 40 33 N | 117 29 07 W |
| South Harbor (historical) | Locale | 14 | Coos | 43 19 44 N | 124 11 44 W |
| South Highline Canal | Canal | 318 | Josephine | 42 24 44 N | 123 19 04 W |
| South Ice Cave Cinder Pit | Mine | 1565 | Lake | 43 34 29 N | 121 05 41 W |
| South Ice Cave Recreation Site | Locale | 1532 | Lake | 43 34 57 N | 121 04 41 W |
| South Indian Reservoir | Reservoir | 1368 | Harney | 43 10 25 N | 118 14 34 W |
| South Inlet | Bay | 15 | Lane | 43 57 40 N | 124 03 29 W |
| South Inlet Post Office (historical) | Post Office | 41 | Coos | 43 15 59 N | 124 19 04 W |
| South Island Campground (historical) | Park | 1806 | Klamath | 42 30 59 N | 122 14 19 W |
| South Jacobsen Reservoir | Reservoir | 824 | Malheur | 44 06 27 N | 117 10 20 W |
| South Jetty | Dam | -5 | Clatsop | 46 13 03 N | 123 59 15 W |
| South Jetty | Dam | 3 | Coos | 43 21 09 N | 124 20 48 W |
| South Jetty | Dam | 0 | Douglas | 43 39 54 N | 124 12 54 W |
| South Jetty | Dam | 2 | Lincoln | 44 36 52 N | 124 03 53 W |
| South Jetty | Dam | -2 | Tillamook | 45 33 59 N | 123 57 24 W |
| South Jetty County Park | Park | 1 | Lane | 44 00 34 N | 124 07 59 W |
| South Jetty Hill Recreation Site | Locale | 68 | Lane | 43 57 16 N | 124 07 16 W |
| South Jetty Nehalem Bay | Dam | 2 | Tillamook | 45 39 19 N | 123 56 04 W |
| South Johns Creek | Stream | | Lane | 44 04 06 N | 123 57 39 W |
| South Jones Prairie | Flat | 1559 | Morrow | 45 09 53 N | 119 13 44 W |
| South Junction | Locale | 383 | Wasco | 44 51 14 N | 121 04 35 W |