Land & Resources Management

Spirit Lake Outflow Safety Improvement Project

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.


Click to view Spirit Lake Outlet project overview sheet

Current System

Learn about the Spirit Lake outflow tunnel that was built for public safety after the Mount St. Helens eruption in 1980.

Pumice plain near Mt St Helens volcano

Core Drilling & Intake Gate Repair

The Forest Service has released a decision on activities to enhance public safety and protection to communities downstream of Spirit Lake. 

Spirit Lake Outlet tunnel joining Spirit Lake to Coldwater Creek

A New Strategy: Spirit Lake Outflow

The Forest Service is engaging stakeholders to develop a long term Spirit Lake Outflow management solution.

Get involved!

Log barrier protecting Spirit Lake Outlet

Science, Maps, Data

Review current scientific reports, data, and information about proposed scientific studies at Mount St Helens.

Review background studies and the current decision frameworks.

1980 eruption materials are highly erodible- cutting away the banks of the Toutle River.

Toutle River System

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

Log barrier protecting Spirit Lake Outlet


Browse photos and videos about the Spirit Lake Project. 

Contact Us

Project Manager: Chris Strebig, 360-891-5052