| South Fork Clearwater River | |
| Map Size: | 300 |
| Pushpin Map: | USA Idaho#USA |
| Pushpin Map Size: | 300 |
| Pushpin Map Caption: | Location of the mouth of the South Fork Clearwater River in Idaho |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | Idaho |
| Length: | 62miles[1] |
| Discharge1 Location: | Stites, about 4miles from the mouth[2] |
| Discharge1 Min: | 44cuft/s |
| Discharge1 Avg: | 998cuft/s[3] |
| Discharge1 Max: | 13800cuft/s |
| Source1: | Confluence of American and Red Rivers |
| Source1 Location: | Near Elk City, Nez Perce National Forest |
| Source1 Coordinates: | 45.8083°N -115.4747°W[4] |
| Source1 Elevation: | 3901feet |
| Mouth: | Clearwater River |
| Mouth Location: | Kooskia, Idaho County |
| Mouth Coordinates: | 46.1458°N -115.9825°W |
| Mouth Elevation: | 1224feet |
| Basin Size: | 1175sqmi[5] |
| Tributaries Left: | Red River (Idaho), Crooked River (Idaho County) |
| Tributaries Right: | American River (Idaho) |
The South Fork Clearwater River is a 62miles[1] long river in north-central Idaho in the United States. Draining about 1175mi2, the South Fork joins with the Middle Fork Clearwater River to form the Clearwater River, a major tributary of the Snake River.
The South Fork has been entirely free flowing since the demolition of the Grangeville Dam in 1963.
The river is formed by the confluence of the American River and Red River in the Nez Perce National Forest at an elevation of 3901feet. The roughly 20miles American River rises at 5200feet and flows generally south to the confluence, while the northwest flowing Red River, rising at 6100feet, is about 25miles long. The American River is sometimes considered part of the main stem.[4] From the confluence the South Fork flows west through a canyon followed by Idaho State Highway 14, receiving the Crooked River from the left and Newsome Creek from the right before reaching Golden, where it receives Tenmile Creek from the left. Further west the river receives Johns Creek from the left, Meadow Creek from the right and Mill Creek from the left, and the gorge deepens to a maximum of some 2000feet as the river swings north near Grangeville. From there the river flows generally north, past Harpster and Stites, before reaching its mouth on the Clearwater at Kooskia, at an elevation of 1224feet.[1]
Grangeville (Harpster) Dam was built on the South Fork in 1910 for hydroelectricity generation. In 1963, the dam was demolished,
The Grangeville Dam, alternatively called the Harpster Dam, was located on the South Fork Clearwater River east of Grangeville. The 56-tallNaN-tall, 440-longNaN-long arched concrete hydroelectric dam was constructed by the Washington Water Power Company in 1910 and 1911. A wooden fish ladder had been installed but it collapsed in 1949. By the 1960s the dam's hydropower facilities had become obsolete. The decision was made to demolish the dam in the interest of fish passage, particularly that of Chinook salmon and steelhead trout.
The dam was destroyed by dynamite at 6:35 PM on August 19, 1963, following two prior detonations that day which had failed to collapse the structure.[6] At the time, the dam was the largest ever to be removed, a record which stood for decades.[7] Today, the entire South Fork and its headwater tributaries are free flowing and unobstructed by dams or major diversions.[8]