Stillaguamish River

The Stillaguamish River is a river in northwest Washington in the United States. It is mainly composed of two forks, the longer North Fork Stillaguamish ) and the South Fork Stillaguamish. The two forks join near Arlington. From there the Stillaguamish River proper flows for 22 miles to Puget Sound. The river's watershed drains part of the Cascade Range north of Seattle.

The Stillaguamish River is formed from the confluence of the North and South Forks, both of which rise in the Cascades. The North Fork rises as several branches in a remote area of Skagit County near Finney Peak, approximately 10 miles north of Darrington. Collecting many tributary creeks, the river flows south, then west through the foothills along the Skagit-Snohomish county line. Tributaries of the North Fork Stillaguamish River include Boulder River and Deer Creek.

Wikipedia