The Sauk is the Skagit's wild twin — an undammed glacial river pouring off Glacier Peak through Darrington, flashier and more untamed than its regulated big brother, and the beating heart of the system's spring wild-steelhead fishery when there is one. It's a National Wild and Scenic river and it fishes like it: milky glacial water that clears slowly, big swung-fly runs, and some of the largest wild steelhead genetics left in Puget Sound. Everything that's true of the Skagit is truer here — these are ESA-listed fish, the catch-and-release spring season exists only on a defined reach under a tightly managed plan, and in many years, including under recent funding cuts, it simply doesn't open. So the Sauk is a river to revere more than to count on: check whether there's a season before you dream about it, read the long glacial drop with patience when there is, and treat every wild fish as the rare and protected creature it is.

• Glacial