A Norwegian trading center on the delta of the Stillaguamish River. Slowly, in the course of many years, the river has deposited its load of silt, inching its way toward the Sound. The town still experiences flood conditions during the spring runoff. To gain a measure of safety, houses formerly were built on foundations several feet high and sidewalks were raised a number of feet above the ground. Flood control measures have reduced the periodic threat. The route continues eastward through farmland and mature fir trees.

In 1892, when a post office was established, the name used was Stillaguamish. The change to the present name was suggested by C. Jorgenson, who filed a plat for the town site. It was for Silvanus, the god of forests and guardian deity of homesteads, flocks and herds in Roman mythology.