These gages continuously monitor changes in water levels. Major increases or decreases in levels trigger warnings which are telemetered to the U. S. Geological Survey in Vancouver. Spirit Lake is in middle right. About 2,500 years ago during the Pine Creek eruptive period, a series of very large lahars traveled down the Toutle River from Mount St. Helens. The level of Silver Lake is now controlled by a dam.
View is West-Southwest.
Mount Shasta is on the skyline.