"THE JOURNEY TO TRINITY" UNDER A NEW MEXICAN morning sky of pale blues and radiant pinks, in teh lavender shadows of the Sacramento Mountains, we converged at the northern edge of Alamogordo. We came from all over the world, an incongruous group, hardly a group at all but that we shared this common desire to stand in a place where few have stood--a place where, half a century ago, the world changed forever.       There weren't many of us, five hundred, perhaps fewer. Families, couples, children, individuals all gathered in the Otero County Fairgrounds parking lot, dressed lightly for the mild autumn weather, which was cool just then, at dawn, but by midday would be baking hot. A solitary motorcyclist in full black leather stared between the high handlebars of his custom chopper, whose gas tank was painted with a grinning skull crowned with thorned wreath and bright red roses. Silent, detached, a congregate of Japanese waited beside their rental. It was impossible not to wonder if any of them were survivors of Hiroshima or Nagasaki. They were about the right age, and could have been among the fortunate schoolchildren who escaped death that morning in August.       We gathered because for our different reasons we wanted to visit Ground Zero, the site where at 5:29:45 Mountain War Time, on July 16, 1945, after a long, rainy night, the physicists who'd worked in secrecy up north of here at Los Alamos witnessed the successful test of their wartime creation: the world's first atomic bomb. We wanted not to pay homage, but stand in remembrance of just what our forebears had wrought there, that midsummer day, in their hope of bringing a brutal war to a quick conclusion.       Some of us, no doubt, had seen photographs of the site. Out in the middle of the highly restricted White Sands Missle Range, on a truly desolate stretch of desert between the Rio Grande River and the Oscura Mountains, stands an obelisk, fashioned of black malpais lavastone, that marks where the detonation took place. It is the loneliest monument on earth. And a modest monument, given that what occurred at that first ground zero could be considered the most fearful event in human history, the place where mankind wrested from God the ability to produce the apocalypse. What had traditionally been seen as divine province was now in our own hands. And this was where we were going, to witness where such a catalyst was ushered into the world.       It is not an easy place to visit. Indeed, few if any other national historic landmarks in this country are as inaccessible. None was ever more fraught with ambiguities. Open to the public for only half a dozen hours or so, on the first Saturdays in April and October, the Trinity Site occupies a small part of the forbidding Jornada del Muerto--the journey of death, as the conquistadors named it--a flat alkaline basin, hedged by bony mountains, speckled with thorny mesquite and soaptree yucca, with cholla and creosote bushes. One may only enter the range as part of a caravan of cars, escorted by state then military police, having set out from Alamogordo.       When we make our way this morning toward Tularosa, a small town north of Alamogordo, the landscape we cross will look just as it did long ago. From Tularosa, we will bear west into a parched scratchland where Billy the Kid drove brand-blotted cattle he had rustled out of Mexico and Texas. Pat Garrett's ghost will be out there, still chasing him, as will a spectral pantheon of legendary rawhiders, prospectors, desperadoes, timbermen, muckers, and other lost souls. As uninhabitable as the terrain will seem, generations have made bloody American history on the stoic, timeless back of this desert. * * * Our convey set out at eight, the sun fully risen, the skies edged by tawny white clouds at every cardinal point, always frothing and changing shapes. I overhead a man say, when we were told to get into our vehicles and turn on our headlights, "This is gonna look like the darnedest funeral procession you ever seen." Alamogordo Chamber of Commerce volunteers, wearing turquoise sport shirts and jeans, walked cheerfully along the rows of cars, handing out bags that contained literature about the Do's and Don'ts of our journey. As I was riding in the passenger seat, it fell to me to read aloud to the others in our car what was written in these documents.       "Dear Trinity Site Visitor," a letter from the Public Affairs Office, Dept. of the Army, began, "The driving distance from Alamogordo to Trinity Site is about 85 miles. During the drive to the site please follow the directions of the city, state, and military police. They are present to insure your safety and protect missile range assests." Then I turned to a schedule of restrictions all visitors were required to obey.       Everyone was bound to stay with the convoy, or risk expulsion. Demonstrations, picketing, sit-ins, political speeches, and other similar activities were prohibited ("I guess the Constitution and First Amendment don't exist out here," I said). No one was allowed to eat or drink at Ground Zero, in order to avoid ingestion of radioactive plutonium, traces of which charge the dust that is raised by a breeze or trampling feet. Application of cosmetics, especially lipstick or balm, is prohibited at the Site. No one was allowed to handle Trinitite or remove any fragments of it from the detonation area--Trinitite being the green-black glassy mineral that was created when the sandy floor of the Jornada melted and fused beneath the nuclear fireball.       Watch out for rattlesnakes, the list advised, and other caveats were listed, too; but above all, this document stated, no one was allowed to take photographs on the way in to Trinity. Anyone caught using a camera would be detained, have his film confiscated, and be conducted back to Tularosa Gate where he would promptly be evicted from the military range. As our caravan moved out onto the highway, police cars behind, I thought: This is no Mount Rushmore, no Statue of Liberty. There are reasons Trinity Site isn't a component in the visual collective consciousness of the nation. * * * ...Fences girdled the narrow two-lane road, and soon we reached the outskirts of sleepy Tularosa. It was hard to believe this almost-ghost town had once been a hinterland Sodom where blood feuds over range, water, and other rights were waged year in and out. Where boys like Oliver Lee short Charles Rhodius over a cattle dispute, and James Smith murdered C.F. Hilton over a land dispute, and Francois Jean Rochas, known as Frenchy, was slaughtered by a man named Morrison, over a horse dispute, and so forth. The days of that particular brand of inglorious glory were over, it seemed, though what were we to make of the technological glories that lay up ahead on this road, built to settle grander disputes in grander ways?       In a violent land, as the valley had once been, there was back then one unwritten rule that did obtain. Known as the Rattlesnake Code, it held that if a man deserved to be killed, it was fair to kill him, no matter what reason you had for killing him, just so long as you warned him first of your intention to kill him. You could shoot him in the back, if you so desired, as long as you told him, let him share in the bad news. There are accounts that before Smith murdered Hilton, who was old and unarmed at the time, he did first say, "Hilton, I'm going to kill you." It was a primitive sort of decorum, but decorum nevertheless.       As the first high-tech tracking dome loomed now on the horizon--resembling a golf ball held at twice arm's length--the contrasts and conundrums of Tularosa Valley began to come into focus. Paradox abounded here. How could I not marvel at the fact that a brief century ago, Tularosans celebrated their first board sidewalk in town with festive huzzahs, pistols shots in the air, dancing, and lots of likker--the same Tularosans who would have grandchildren who were knocked out of their beds one quiet summer morning when that first atomic blast backlit the San Andres, and sent a massive roiling of radioactive ash into the heavens? How could I not marvel at the fact that the cowboy wars of the nineteenth century, famed for their ferocity, were but modest overtures to the scenes that would manifest out here in the desert, and beyond, in the century to come.       At that moment when the Little Boy bomb was dropped without warning on Hiroshima from the Enola Gay, the humble Rattlesnake Code, absurd and Wild Western as it was, became a comparatively gentle, decorous bit of etiquette from a bygone era.... (Excerpted from THE PLACE WITHIN: Portraits of American Landscapes by Twenty Contemporary American Authors, edited by Jodi Daynard, published November 1996 by W.W. Norton, $23.00, ISBN 0-393-03999-4.)