Invasion

Invasion Description

1st Record: Salem/OR/Willamette River (1893, Lampman 1946; Hughes and Gammon 1987);

Geographic Extent

north of I-84N at Rooster Rock State Park/OR/Rooster Rock Slough ( 2001, USGS Nonindigenous Aquatic Species Program 2018); Salem/OR/Willamette River (1893, Lampman 1946; Hughes and Gammon 1987); Portland/OR/Columbia Slough (1905, Lampman 1946; 2008, Van Dyke et al. 2009); Portland/OR/Willamette River (Farr and Ward1993); Portland/OR/Columbia Slough (Van Dyke et al. 2009); OR-WA/Columbia River (Chapman 1942; Lampman 1946); northwest of Rainer/OR/Dibblee's Slough, Dibblee Point (2001, USGS Nonindigenous Aquatic Species Program 2018); North of Knappa junction or Brownsmead junction off hwy 30/OR/Blind Slough (2009, USGS Nonindigenous Aquatic Species Program 2014); north of Clatskanie off hwy 30/OR/Clatskanie Slough (2009, USGS Nonindigenous Aquatic Species Program 2014); Crimms Island (downriver from Longview WA/OR/Columbia River (2004, Haskell and Tiffin 2011)