For nearly 70 miles, the Stillaguamish River flows all the way from the North Cascades into the Puget Sound. Many tributary streams join its journey to the bay as it meanders south, then west, then forks around islands before reconnecting with itself. The lack of major dams allows it to flow freely, and it is a wild river indeed, rushing through narrow, rocky canyons; rising and falling—fast—by a dozen or more feet; and bringing life to the new- and old-growth trees that gather at its edges. The river and its basin also provide a refuge for many “keystone” species: Pacific salmon, beavers, gray wolves, woodpeckers, big-eared bats, hummingbirds. These irreplaceable critters play such a crucial role in holding an ecosystem together that were we to lose any of them, the chain of events would cause Washington’s ecological community, and so much of its beauty, to fall apart. The Stillaguamish is more gray than blue, even under bright skies, but life here is colorful because of it, as it pours itself into the biodiversity it sustains.