GPS benchmark installation just below crater of Mount St. Helens.
![GPS benchmark installation just below crater of Mount St. Helens....](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/vhp_img463.jpg?itok=Xof2dyxJ)
Detailed Description
Epoxy is used to cement a permanent survey marker at a field location just below the crater of Mount St. Helens (north flank). The benchmark is used to create a fixed location for future GPS surveys.
Sources/Usage
Public Domain.