Found this link to his “Wilderness Letter” at the WTA blog.

Something will have gone out of us as a people if we ever let the remaining wilderness be destroyed; if we permit the last virgin forests to be turned into comic books and plastic cigarette cases; if we drive the few remaining members of the wild species into zoos or to extinction; if we pollute the last clear air and dirty the last clean streams and push our paved roads through the last of the silence, so that never again will Americans be free in their own country from the noise, the exhausts, the stinks of human and automotive waste. And so that never again can we have the chance to see ourselves single, separate, vertical and individual in the world, part of the environment of trees and rocks and soil, brother to the other animals, part of the natural world and competent to belong in it. Without any remaining wilderness we are committed wholly, without chance for even momentary reflection and rest, to a headlong drive into our technological termite-life, the Brave New World of a completely man-controlled environment. We need wilderness preserved–as much of it as is still left, and as many kinds–because it was the challenge against which our character as a people was formed. The reminder and the reassurance that it is still there is good for our spiritual health even if we never once in ten years set foot in it. It is good for us when we are young, because of the incomparable sanity it can bring briefly, as vacation and rest, into our insane lives. It is important to us when we are old simply because it is there–important, that is, simply as an idea.

Stegner was a Bay Area guy. There’s a bench named after him at Long Ridge Open Space Preserve.

The inscription on the plaque reads:

“…to try to save for everyone, for hostile and indifferent as well as the committed, some of the health that flows down across the green ridges from the Skyline, and some of the beauty and refreshment of spirit that are still available to any resident of the Valley who has the moment, and the wit, to lift up his eyes unto the hills.”

Stegner had some chops as a writer, no doubt about it.