Environmental DNA quantitative PCR results for water samples collected in 2018 at USGS streamgages downstream of Columbia River Basin reservoirs that are considered to have moderate to high suitability for invasive dreissenid mussels. Water samples were tested for DNA of dreissenid mussels, kokanee salmon, and yellow perch. This is version 1.1 of this data release. The Kokanee_Perch_eDNA data and metadata files have been revised to correct for improper attribution of 16 samples. For access to previous versions, please contact the Point of Contact identified on this page. First Posted March 29, 2019 Revised July 19, 2019, ver 1.1