This is the Stillaguamish River from WDFW's Boe Road river access just off Marine Drive on the left, upstream to the confluence with Cook Slough coming in from the south and the village of Silvana. The Stilly North Fork is minor to Hat Slough, which is actually the much larger South Fork. Cook Slough is the main channel, but has a weir upstream.
My visit was near high tide on this tidewater river. The bars and beaches were covered with water until I reached the cobble bar at the corn field about a mile-and-a-half upriver from Boe Road. The field that looks barren here was in tall corn the September day when I walked up off the bar to stretch my legs. (Thanks to Google for this satellite shot, with my added labels.)