Blacktails in turn are the mainstay of the Alexander Archipelago wolf, a smaller, darker subspecies of the gray wolf. During the past decade, researchers have learned that some packs spend a surprising amount of time catching salmon, too. Undisturbed watersheds favor strong spawning runs: The towering shade keeps streams cool, fallen trunks slow down currents and create pools, woodland nutrients fertilize the food chain that young fish rely upon. Closing the circle, generations of returning salmon help grow those very trees over time as fish-eating wolves, bears, eagles, gulls, and other animals spread around carcasses and excrement, all loaded with nitrogen and phosphorus from the ocean realm. It's like sprinkling Mrs. Nature's Supergro Mix onto a garden bed.

Forest economists have different ways of describing such habitats. "Overmature" is one. "Decadent," and "stagnating" are popular. The favorite is still "falling down and going to waste." All imply that where we don't harvest a forest to stimulate a new round of growth, the system lingers past its prime and decays. Well, they have a point, but only from the standpoint of maximum timber production. In terms of the maximum production of life, they are not seeing the forest for the trees.

Ground littered with broken branches and the trunks of titans that crashed to earth, creating openings above; all those mulches and mushrooms and composting tree tissues and burrowing, wriggling, scavenging little animal forms—these are signs of vitality in a woodland. The older the forest, the more complex its structure and ecological functions, and the wider the array of niches for flora and fauna. From lichens and liverworts to millipedes and mink, the richest assortment of life-forms in the rain forest ecosystem is housed within old-growth stands. They are the countryside's hot spots of bio-diversity. Antiquity is their prime.

One cure for age discrimination against elderly habitat is to hike through what replaces it after logging. Rain forests erupt with vegetation; it's their specialty. In clear-cuts, the result is a barricade of flexible shrub stems, spruce sapling needles, and sharper thorns. When surveying clear-cuts for signs of wildlife, the Sen Boys jokingly rated each bushwhack on a misery index from one to ten.

By four, you're in an obstacle course where forward progress requires using your hands as much as your feet. Feet rarely touch the ground after six. They are either searching for balance atop springy branches or caught in—well, difficult to say, because you can't see your feet through the leaves. Jungle-gymming up a mountainside where the branches all point downhill counts as an eight. One step forward, two stumbles back. When you grab for something to stop your slide, it's too often Oplopanax horridum—devil's club, the thorniest plant around.