ANSEL ADAMS: An Autobiography. By Ansel Adams with Mary Street Alinder. New York Graphic Society. 400 pp. $50.

AS A PILGRIM to Yosemite, I remember being scarcely out of the parking lot when I stopped in my tracks and stood gawking at one of our primary natural monuments. It loomed in redoubtable weathered repose amid its half-circle of students and cameras, it wore a Stetson hat like it knew how, and there was no other eminence upon the American earth that this could be but Ansel Adams.

A singular grizzled grace is our image of the late and hallowed photographer-environmentalist, and Adams takes his customary workmanlike care to preserve that in these pages. Posthumously -- he passed to history at age 82 in April 1984 -- the Adams profile still looms formidably here, from the silver-spoon San Francisco child who plagued the household by asking "Does God go to the toilet?" to the famous photographic craftsman who answered when asked if he felt a heightened consciousness at the instant of shutter click, "I practice Zone, not Zen." But he also tellingly remarks, "Relatively few really know me, but millions know the folk hero they think is me." It would take a confessional barn-burner of a memoir to change our view of Ansel Adams the stalwart yet sensitive Sierraman, and this isn't that.

What Ansel Adams: An Autobiography does nicely manage to be -- it's a tribute to the book's quiet but beautiful balance of design that this works -- is a simultaneous family album-cum-memoir and retrospective of the Adams photographic canon. Not unexpectedly, the inimitable exactness Adams gave us from his camera wasn't duplicable from his word processor. He recounts various social occasions and ceremonies which do not retell as niftily as they must have uncorkd at the time, and he provides numerous ritual bows to family, friends, colleagues, patrons. Be prepared for some ancillary Ansel throughout these pages. A deep focus sometimes has been deliberately chosen against. He mentions that his grandfather "built a prosperous lumber business." In fuller and more interesting perspective, William J. Adams was a baron among early cut-and-run timbermen who took down the magnificent virgin forests of Puget Sound, once vowing when a competitor outdealt him: "We will get even as sure as there is a God in Israel." Also, there probably was more to Ansel Adams' thoughts than is in here about the rise of pictorial magazines such as Life, which proffered to artistic photographers a mass audience previously undreamed-of but then frequently truncated or scrapped the photo essays they did on assignment. And his (and everybody else's) role during the Sierra Club's internecine combat in its David Brower era needs an incisive neutral observer. If we, and Ansel Adams, are lucky in his eventual biographer, a more complicated and compelling soul may emerge from under the shadow of that Stetson.

Meanwhile, anecdotes have to sustain us, and they do. With wonderful amiability Adams lets Alfred Stieglitz and Georgia O'Keeffe steal the scene whenever they show up. Tales are told of dozens of fine photographers and other artists -- and a hilarious one about the mobile moguldom of Darryl F. Zanuck. Here in his last public words Adams is permanently angry at only a chosen few -- fellow photographers William Mortensen (exponent of allegorical portraiture that Adams deemed "fuzzy-wuzzy") and Edward Steichen ("As a friend said, 'He has the ability to make women cry and he revels in it.'") and President Ronald Reagan, former employer of James Watt. The Prez may have won a PR moment in 1983 by actually sitting down with Adams, the symbolic environmentalist, for 55 minutes, but Adams now gets to aim an earful at posterity: "I was negatively impressed with Reagan's failure to discuss or challenge my opinions at every turn . . . The flow of bilge from the Reagan administration is a blot upon our history of literacy."

For all his environmental spokesmanship that capped a career of outdoor life, Adams well knew what would give him his own mark in our history. The photographs, the hauntingly luminous photographs. Here in their half- century panorama, Adams' pictures have never spoken better for themselves, and thus for him. Of this book's 277 illustrations some 120 are Adams' nature compositions, and along with lesser-seen ones his classics shine anew here -- "Monolith, The Face of Half Dome"; "Mount Williamson . . . from Manzanar"; "Moonrise, Hernandez, New Mexico"; and that astounding eye-symphony, "Winter Sunrise, the Sierra Nevada, from Lone Pine," with the Sierra peaks whitely sunlit and teased by cloud tendrils, the dark undulation of leftover night shadowing below them, and below that a spectral line of trees and the lone tiny grazing horse which somehow lends resounding magnitude to all else.

"My vision established its own groove," writes Adams, "as I know I have been derivative of myself for fifty years." He indeed seems to have decided early, and I think rightly, that photodom's interpreter of the Sierra Nevada's magnificence was plenty to try to be in one lifetime. A recent critic tut-tutted Adams' trademark exactness in portraying nature -- "a poet more of light than of personalities." What, are we so far gone down the narcissistic path that the face of Half Dome counts for less than human physiognomy? But Audubon, baby, if you ever hope to get the cover of People you're gonna have to lay off the birds and whip out some portraits of, well, you know.) Ansel Adams caused us to perceive what we should have known was there, but didn't know how to see. Early in these pages he recalls an instant from boyhood, on a summer afternoon when he was setting the table for supper:

"The persistent fog had lifted and the warm sun streamed into the dining room through the west-facing windows. . . .The light was unforgettable."

Exactly.