1950 Jackson Creek, Skagit County Debris Flow (washingtonlandscape.blogspot.com)The Highway 9 corridor from Sedro-Wooley to Kendal follows the Samish River Valley and then after crossing a very subtle divide follows the South Fork Nooksack River Valley. I previously noted the alluvial fans associated with steams that flow into the Sanish River Valley (alluvial-fans-altering-samish-river).