The Samish River originates on a low divide in Whatcom County, and its tributary, Friday Creek, originates in the hills south of Bellingham. The river continues its southwesterly flow through Skagit County and outlets into Samish Bay in Puget Sound.
The Samish River has its source at a low elevation in Whatcom County, with its tributary, Friday Creek, originating nearby in the hills south of Bellingham. The river travels southwestward through Skagit County before reaching Samish Bay in Puget Sound.