The Bluegill landslide is a large, naturally-occurring landslide located about 22 miles west of Twin Falls and 6 miles west of Buhl, in south-central Idaho. The landslide is predominantly on public land administered by the BLM, with other portions on state and private property.
Bluegill is part of a larger landslide complex that forms an area in the Salmon Falls Creek drainage named Sinking Canyon. The last major landslide movements in Sinking Canyon occurred in the summer of 1937, when several acres of farmland were lost over a period of several days into the existing canyon. The 1937 event was like many landslides that have occurred in this area since the inception of the canyon.
The most recent movement of the Bluegill landslide occurred in late 1998 or early 1999, brought to the attention of the BLM when, in 1999, recreational rock climbers noted the formation and widening of fractures in the basalt cliffs that form the canyon rim.
Initial monitoring determined that about 11 acres of the canyon rim had moved over a period of several months to a year. These movements created a dam that forms a lake approximately one mile long and averaging about 130 feet wide. The primary hazard currently associated with the landslide is a possible breach of this dam, which could cause flooding downstream.
As part of ongoing efforts to address possible public safety concerns, the BLM, in coordination with the US Geological Survey (USGS), has conducted an assessment of the landslide, examined mitigation options, and identified alternatives for further study and monitoring of the landslide. To date, landslide movement has been minimal and remains under observation by the BLM and the USGS.
For additional information, contact the BLM Burley Field Office at (208) 677-6641.