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.
Learn how the forest is working towards a collaborative watershed management plan for the health & safety of the Toutle River watershed and affected communities.