Spirit Lake
The Gifford Pinchot National Forest is responsible for operating, maintaining, and repairing the 1.6 mile Spirit Lake tunnel and the engineered channels at Castle and Coldwater Lakes. Constructed in 1985, the tunnel provides the only outflow for Spirit Lake. To address annual tunnel operation in this dynamic volcanic landscape and to contribute to geologic hazard risk reduction to downstream communities, the Forest Service works with federal, state, and local partners.
The Forest Service is currently developing a collaborative strategy to create more sustainable and safer options for long term management of Spirit Lake Outflow to achieve ecological, economic and public safety needs.
See this Video about the Mount St Helens Eruption; Spirit Lake and Toutle River Watershed.
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Contact Us
NEPA Coordinator: Kelsey Jolley
Email: SM.FS.SpiritLake@usda.gov
Phone: 360-891-5021
Current System
Learn about the Spirit Lake outflow tunnel that was built for public safety after the Mount St. Helens eruption in 1980.
Intake Gate Replacement and Geotechnical Drilling
Intake gate replacement work is underway and is anticipated to continue through 2027. Geotechnical drilling is tentatively scheduled to begin in 2025.
Spirit Lake Outflow Safety Improvement Project
Gifford Pinchot National Forest is conducting stakeholder engagement and environmental analysis to identify a long-term Spirit Lake outflow solution.
Spirit Lake: Science, Maps, and Data
Review current scientific reports, data, and information about proposed scientific studies at Mount St Helens. Review background studies and the current decision frameworks.
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