The Rio Blanco rises from a series Andean glacial lakes high in the Aysen region of Patagonia. It’s a river born of ice and rock, and it slices through imposing, tall country before it throws itself into a tight basalt canyon deep in the heart of Chile’s Valdivian rainforest, creating a frothy morasse of nearly impassable rapids and waterfalls that have confounded river runners for decades. Most simply deem the canyon run of the Rio Blanco “unrunnable” and look for friendlier water.

Some years ago, while working as a newspaper journalist in the mountains of Colorado, I remember having an epiphany that I couldn’t help but include in a piece I did for the paper on fall fly fishing. At the time, we were enjoying a really nice Indian summer — we had a blustery start to September and then, as things are prone to do in the southern Rockies, those perfectly blue and cloudless skies came back, along with warm temperatures and that flawless golden hue that graces the aspens and the cottonwoods of the West every autumn.