Monitoring station VALT was installed on the crater floor of Mount St. Helens in 2006.

Monitoring station VALT was installed on the crater floor of Mount St. Helens in 2006. It was called VALT because a vault-like structure about the size of a large doghouse was built into the rocky deposits to protect the state-of-the-art (at that time) broadband seismometer from environmental variables such as temperature and humidity. The station was dismantled on June 6, 2024, as Crater Glacier (pictured in the distance to the left of the lava dome) advanced too closely. VALT will be moved to a new location.