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Federal
Digital terrain model of upper North Fork Toutle River valley, Washington, derived from historical topographic maps
Department of the Interior —
This digital terrain model represents historical elevations along the valley of the North Fork Toutle River upstream of its confluence with the Green River in Cowlitz... -
Federal
Digital terrain models of Spirit Lake blockage and Mount St. Helens debris avalanche, based on 1980-2018 airborne photogrammetry surveys
Department of the Interior —
The lateral blast, debris avalanche, pyroclastic flows, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the...