Purcell Trench

Purcell Trench
Kootenay Lake in the Purcell Trench (north is to the left)
Length179 miles (288 km)
Geography
Coordinates49°39′N 116°54′W / 49.65°N 116.90°W / 49.65; -116.90

The Purcell Trench, also known as the Kootenay River Valley is a large valley on the western side of the northern part of North America's Rocky Mountains. The trench extends approximately 179 miles (288 km) from Lake Pend Oreille, Idaho, down the Kootenay River (north) to Kootenay Lake, up the north arm to Duncan Lake. It joins the Rocky Mountain Trench another 50 miles (80 km) northward at the south tip of Kinbasket Lake, in British Columbia.[1] The trench bottom is 1 to 7 miles (1.6 to 11.3 km) wide and is 1,750 to 2,100 feet (530 to 640 m) above sea level. The trench is nearly a straight north or south line.[2] Some of its topography has been carved into U-shaped glacial valleys, it is primarily a product of geologic faulting. The trench splits the Columbia Mountains between the Purcell Mountains on the east and the Selkirk Mountains on the west.[3]

  1. ^ Doughty, P.T. & R.A. Price; Department of Geological Sciences, Queen’s University, Kingston, Ontario K7L 3N6, Canada; Geology of the Purcell Trench rift valley and Sandpoint Conglomerate: Eocene en echelon normal faulting and synrift sedimentation along the eastern flank of the Priest River metamorphic complex, northern Idaho; GSA Bulletin; September 2000; v. 112; no. 9; p. 1356–1374; 19 figures; 3 tables
  2. ^ W. C. ALDEN; Physiography and Glacial Geology of Western Montana and Adjacent Areas, Geological Survey Professional Paper 231; United States Government Printing Office, Washington, D.C.; 1953
  3. ^ Menounos, Brian & Osborn, Gerald & Clague, John & Luckman, Brian. (2009). Latest Pleistocene and Holocene glacier fluctuations in western Canada. Quaternary Science Reviews. 1877. 71-1. 10.1016/j.quascirev.2008.10.018.