The Johnson Creek Watershed contains volcanoes, Missoula flood deposits, and the oldest rocks in the East Portland Metro. Though this dramatic geologic history is usually obscured by vegetation and development, the creek cuts a slice down through the geologic layer cake to reveal the rock formations underlying Gresham, Southeast Portland, and Milwaukie. Paul Edison-Lahm will lead this virtual tour of the Watershed and give tips for exploring Portland's Eastside.
Paul Edison-Lahm is an amateur geologist, GSOC board member, and coordinator of our annual Downtown Portland Building Stone tours. He lives in Southeast Portland in the Johnson Creek watershed. Paul's presentation was developed in collaboration with geologist and GSOC Vice-President Sheila Alfsen, and the Johnson Creek Watershed Council for their September 2017 Science Pub.