Keywords: Mudline from 1980 St Helens lahars next to Muddy River.jpg Mount St Helens Mudline Nearly 135 miles 220 kilometers of river channels surrounding the volcano were affected by the lahars of May 18 A mudline left behind on trees shows depths reached by the mud A scientist middle right gives scale This view is along the Muddy River southeast of Mount St Helens October 23 1980 by Lyn Topinka USGS/CVO USGS image from http //vulcan wr usgs gov/Volcanoes/MSH/SlideSet/ljt_slideset_old html 1980-10-23 Lyn Topinka USGS/CVO PD PD-USGov Metadata from image 1980 eruption of Mount St Helens Volcanic damage Lahars |