| South Fork Breitenbush River | |
| Map Size: | 300 |
| Pushpin Map: | USA Oregon |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the South Fork Breitenbush River in Oregon |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Oregon |
| Subdivision Type4: | County |
| Subdivision Name4: | Marion |
| Length: | 10miles[1] |
| Source1: | Russell Lake |
| Source1 Location: | Mount Jefferson Wilderness, Willamette National Forest, Cascade Range |
| Source1 Coordinates: | 44.7147°N -121.7994°W[2] |
| Source1 Elevation: | 5886feet[3] |
| Mouth: | Breitenbush River |
| Mouth Location: | Breitenbush Hot Springs |
| Mouth Coordinates: | 44.7797°N -121.9647°W |
| Mouth Elevation: | 2277feet |
The South Fork Breitenbush River is a 10miles tributary of the Breitenbush River in the U.S. state of Oregon.[2] The river flows generally northwest from Russell Lake in the Mount Jefferson Wilderness of the Cascade Range to near Breitenbush Hot Springs, where it merges with the North Fork Breitenbush River to form the main stem.
The South Fork receives Lake Creek and Roaring Creek, both from the right, as it descends through the wilderness and the Willamette National Forest.[4] From the confluence of its forks, the main stem Breitenbush River flows about 11miles further to its confluence with the North Santiam River in Detroit Lake.[5]
The Pacific Crest Trail crosses the South Fork near Russell Lake.[4] South Breitenbush Trail, which parallels the river for about 6miles in its upper reaches, offers opportunities for hiking and backpacking at elevations ranging from 3050feetto5850feetft (toft) above sea level.[6]
South Breitenbush Gorge Trail, along the river closer to its confluence with the main stem, passes through older Douglas-fir and western hemlock forest. This trail, ranging in elevation from 2300feetto2800feetft (toft), is 2.5miles long. A side trail leads to a narrow canyon, about 300feet long, where the river flows between walls of basalt.[7]