Troutdale Formation

field trip

Columbia Gorge Field Trip: Troutdale Formation and Boring Basalt (cwmh2o.com) The CwM team could not resist the early summer-like weather in the Pacific Northwest and took a “Geology-Friday” field trip into the Columbia River Gorge. Their trip took them east from Portland to the Sandy River, along the Historic Columbia River Highway through Corbett, with stops at the Latourell and Bridal Veil Falls, and back west along the banks of the Columbia River. The goal was to find outcrops of the Troutdale Formation, parts of which make up an important groundwater source in the Portland metro area and part of the City of Portland’s Columbia River Wellfield.

Bartonian (Wikipedia) The Bartonian is, in the International Commission on Stratigraphy’s (ICS) geologic time scale, a stage or age in the middle of the Eocene Epoch or Series. The Bartonian Age spans the time between 41.2 and 37.71 Ma. It is preceded by the Lutetian and is followed by the Priabonian Age.

Round Lake Loop Interpretive Trail Guide (PDF) (clark.wa.gov) This guide describes various water related features around Round Lake which corre spond to numbered trail-side posts.