1. Geologic map of the Greater Portland Metropolitan Area and surrounding region, Oregon and Washington
2020. 2022-07-13T18:00:04Z. 2022-08-23T21:34:46Z. Geological Survey (U.S.), cartographer. U.S. Department of the Interior, U.S. Geological Survey. English. cartographic image,text. Public. Oregon, Clackamas County, Columbia County, Marion County, Multnomah County, Yamhill County, Washington (State), Cowlitz County, Clark County, Clackamas County., Columbia County., Marion County., Multnomah County., Yamhill County., Clark County., and Cowlitz County.
