Castle Lake, Mount St. Helens, in the winter 2013. View to SE.

Castle Creek was dammed by the May 18, 1980 eruption of Mount St. Helens (downed logs still visible along the shores), eventually forming Castle Lake. A sudden rise in the lake level could lead to a break in the debris dam and flooding of the North Fork Toutle River valley. Lake levels are remotely monitored for this specific hazard. View to the southeast, along the shores of Castle Lake, Mount St. Helens.