20230210 09262500 1.0 TRUE SPW_GIS_PROD.SPW_GDBA.HYDROGRAPHY__ASSESSMENT__snohomish_mainstem_channels Mainstem Snohomish channel tracings digitized from 1933, 1947, 1955, 1965, 1974, 1984, 1991, 1998, 2001, 2007, 2011, and 2012. Historic photos were scanned and georeferenced.