Castle Creek is a tributary of the North Fork Toutle River on the flank of Mount St. Helens in Washington state. It rises about two miles (three kilometers) northwest of the crater rim (46.21690°N 122.23934°W / 46.21690; -122.23934 (Castle Creek source))[1] and flows generally to the northwest. The outflow of Castle Lake joins the creek at the lake's north end (46.258°N 122.272°W / 46.258; -122.272 (South Fork Castle Creek confluence)) after traveling a few hundred meters on the South Fork Castle Creek.[2] It joins the North Fork Toutle River at 46.28302°N 122.29359°W / 46.28302; -122.29359 (Castle Creek mouth), elevation 2,200 feet.[1][2]

Castle Creek
Aerial view of Castle Creek and Castle Lake. Part of Mount St. Helens is visible in the upper left corner of the image.
Location
Country	United States
U.S. State	Washington
County	Cowlitz
County	Skamania
Physical characteristics
Source
• location	West flank of Mount St. Helens
• coordinates	46.21690°N 122.23934°W / 46.21690; -122.23934 (Castle Creek source)[1]
• elevation	4,275 feet[2]
Mouth	North Fork Toutle River
• coordinates	46.28302°N 122.29359°W / 46.28302; -122.29359 (Castle Creek mouth)[1]
• elevation	2,200 feet[2]
Basin features
Tributaries
• left	South Fork Castle Creek
Waterbodies	Castle Lake (South Fork)

Castle Lake was created by an avalanche subsequent to the May 18, 1980 eruption of Mount St. Helens which blocked South Fork Castle Creek.[3] Pre-1980 maps show this area as "Castle Creek Marsh".[4][5]

References