ou just don't get it, do you? This is a czarist nation, a fascist state. They control everything. They tap my phone. They'll do anything to stop me. We're the front lines, man, fleas fighting a giant.''

It is a clear, crisp, gorgeous winter afternoon in the high desert in Nevada, and Michael Heizer, who has spent the past 32 years and many millions of mostly other people's dollars constructing ''City'' -- one of the biggest sculptures any modern artist has ever built, one and a quarter miles long and more than a quarter of a mile wide -- is in a state of extreme agitation, even for him. His pique is rising as he maneuvers his truck down a bumpy mountain pass, filling the truck's cabin with cigar smoke. I sense that he's rather enjoying himself.

We are driving through Murphy Gap. Pinyon and juniper cluster along the slopes on either side. This narrow, serpentine passage of astonishing beauty cuts through the Golden Gate Range, far from civilization. Aside from Heizer's voice and the truck's engine, there is an endless, empty, engulfing silence.

Coal Valley, on the eastern side of the mountain range, is a desolate, flat plain of yellow rabbit brush and silver sage for grazing cattle. To the west, Heizer's valley, Garden Valley, is vast and nearly uninhabited. Size is deceptive out here. ''City'' looks from the edge of the valley like a low-lying bump, barely visible. When you drive just a mile from it, south across the valley, it basically disappears into the brush. But picture a sculpture the size of the Washington Mall, nearly from the steps of the Capitol to the Washington Monument, swallowing many of the museums on either side. That's how big it is. Only once you're inside do you see all the mounds, pits, passageways, plazas, ramps and terraced dirt, most of the sculpture having been dug below ground level, masked from outside by berms. The shapes echo the mountains. ''I'm not selling the view,'' Heizer contradicts when I mention this. ''You can't even see the landscape unless you're standing at the edge of the sculpture.'' True. Even so, the echoes are plain as day.

We are maybe 30 miles from Nellis Air Force Base and the military's supersecret Area 51, and more than 100 miles from Yucca Mountain, where the federal government, if all goes as planned, will begin to collect the nation's nuclear waste in 2010. Trains will transport the waste from across the country, through the middle of Atlanta and Chicago and Salt Lake City and Kansas City, to Caliente, a town just north of here. From there, more than 300 miles of track will have to be laid, at a cost of more than $1 billion, to carry the waste the rest of the way.

As it is currently conceived, the route will cut across Garden Valley, within ear- and eyeshot of Heizer's sculpture and the ranch right next to it where he lives, a kind of survivalist compound of cinder block and solar panels, an oasis of cottonwoods and wild plum trees in the middle of a wide, empty plain. Having moved long ago to this virtual end of the earth, and having also moved heaven and earth to build in isolation his immense sculpture, Heizer now finds the federal government is plotting, as he sees things, to ruin it and him.

Heizer knows it's highly unlikely that he or anyone else will suddenly stop Yucca cold, but he says he's hoping at least to persuade Department of Energy officials at this 11th hour to redirect the tracks next door through Coal Valley and Murphy Gap. Of course he is deeply pessimistic. ''I've always been a pessimist,'' he tells me, ''but now I think things are going to get really, really bad.'' Squinting into a fresh plume of cigar smoke, which rises like a dark cloud around him, he starts imagining first the rail, then wells, then electric power lines invading the valley, while ''sniveling toady'' politicians, as he calls them, do nothing.

His soliloquy crescendos, linking defense contractors like Kellogg Brown & Root and Bechtel to the government as a sinister cabal machinating against him -- ''I wouldn't be surprised if they sent out a hit squad to kill me!'' -- when the silence of Murphy Gap is suddenly shattered by a heart-stopping boom.

An F-16 buzzes our truck. It looks as if it can't be more than 100 feet overhead, turned sideways to maneuver low through the snaking pass. Then as quickly as it appears, it's gone.

Who knows? I think. Even paranoids may be right sometimes.

his is a story about a man, his dream and a railroad. Everything in it is outsize, including the landscape. It's otherwise a familiar Western saga, pitting a brooding, determined loner against big, bad Washington, except that in this case the hero's personality is at least as radioactive as the train barreling toward him.

At 60, with hawkish steel gray eyes, a kind of wary stare, a deeply lined face and haphazardly combed-over hair, Heizer is still gaunt from a decade-long battle with a neurological disorder that left him weak and in crippling pain. If illness reinforced his native martyr streak, it also strengthened his resolve, making the sculpture a mission. The knowledge that the government or his body or both could prove his work's undoing makes him more fierce at the same time that he seems swallowed up in his clothes: dusty khakis, a checked vest over a plaid shirt, a sheepskin hat with earflaps and cowboy boots. He affects the look of other ranchers in this hardscrabble stretch of range, a resemblance that partly belies his upbringing.

Born in Berkeley, Calif., Heizer comes from an accomplished family of academics, geologists and miners with some history in Nevada, a history that he's proud of and that explains how he ended up making art here. During the 1960's, sculpture moved outdoors, and Heizer was one of the movers. In the early 60's, Claes Oldenburg, Carl Andre and Walter De Maria were digging holes or talking about digging holes, making performances out of the process. De Maria was imagining milelong parallel walls in the desert, and Robert Smithson was mapping the New Jersey landscape, visiting quarries, making ''Nonsites'' out of rocks he collected and conceptualizing Earth Art, which became a catchall term for disparate experiments. It was an era of chest-thumping, clashing personalities, proclaiming to remake art from scratch, and Heizer fitted right in.

His contribution was to go West. The Abstract Expressionists had linked American art with scale. Jackson Pollock's paintings were said to refer to the Western landscape. Heizer took the idea to its logical next step. He literally made art out of the Western landscape, replacing scale with size: his works didn't just allude to big things; they were enormous. The bigger the hole or ditch he dug, the more monumental the sculpture. Negative sculpture, as Heizer called art made out of the space left behind from digging, crept into the mainstream consciousness, even if many people have never heard of him. Maya Lin's Vietnam Veterans Memorial and the memorial design for ground zero are both riffs, in part, on Heizer's negative vocabulary.

Adventuresome patrons and dealers like Robert Scull, Heiner Friedrich, Richard Bellamy, Virginia Dwan and Sam Wagstaff gravitated to the moody Westerner with the Ayn Rand vision and smoldering charm. They bankrolled his most radical art adventures. He dug holes in the Sierra Nevada, near Munich, Germany, and elsewhere; mostly the holes were shallow, the slopes gentle. But awe, even fear, was sometimes part of the work: the fear a viewer might feel about falling into one of the deeper holes. Heizer also scattered dyes and powders and drove a motorcycle to leave tire tracks, like drawings, across dry lake beds. He dug trenches, at intervals across hundreds of miles in the desert.

His best-known work was ''Double Negative,'' for which he cut a 1,500-foot-long, 50-foot-deep, 30-foot-wide gash onto facing slopes of the Mormon Mesa in Nevada by blasting and scraping away 240,000 tons of rock. It became a landmark of Earth Art, never mind that Heizer wanted nothing to do with any movement -- or, increasingly, with most other artists. ''I burned hot and was making something totally original,'' he recalled one afternoon while shuffling through some stacks of photographs of ''Double Negative'' in his office. ''It was a moment of genius and unprecedented.''

Then he couldn't resist taking his usual gratuitous whack at Smithson, his former friend, whose ''Spiral Jetty'' in Utah, finished just after ''Double Negative,'' became an icon of Earth Art. Smithson, as Heizer sees it, ''just copied my M.O., did a complete heavy borrowing, an identity theft.'' Smithson died in a plane crash in 1973. Over the years, most of Heizer's friendships with artists he knew then have fallen away.

In 1972, Heizer acquired land in Garden Valley and began work on the first part of ''City,'' his own version of Easter Island or Angkor Wat: a modernist complex of abstract shapes -- mounds, prismoids, ramps, pits -- to be spread across the valley. It was to be experienced over time, in shifting weather, not from a single vantage point or from above but as an accumulation of impressions and views gathered by slowly walking through it. Artists in the 1960's and 70's -- Donald Judd, Andre, De Maria, Smithson, others -- were pushing sculpture off its pedestal. This was sculpture pushed all the way into the Western desert, the sort of work that you couldn't buy or sell even though it was very expensive to produce. Its materials were dirt and rock and cement and rebar, not marble or porcelain or bronze, and its tools were not chisels but heavy machinery.

The sculpture was meant not just to employ nature -- the soil, sun and air -- but also to make art out of engineering. Heizer traded in his paintbrush for a bulldozer, which, not incidentally, he could operate himself, unlike some of the other so-called Earth artists, but the work still required a crew. Artists have always had assistants. Heizer's happened to be construction workers with cranes and forklifts.

''City,'' in its vastness, was meant to synthesize ancient monuments, Minimalism and industrial technology. The work derived inspiration from Mississippian tumuli (ancient North American mounds), the ball court at Chichen Itza in the Yucatan and La Venta in southern Tabasco, where his father, a prominent anthropologist and archaeologist, had excavated. At the same time, it suggested airport runways and Modernist architecture.

Heizer resists such strict comparisons, stressing his basic abstract impulses. ''The trouble is,'' he explained to me, ''once you say something about a source, then you've pegged it down, and so now I'm reluctant to say anything. If I say I developed 50 different shapes from Mississippian tumuli, that doesn't mean they're copies of tumuli -- I'm not ripping off those shapes. I said I derived some of the shapes from the serpent motif at Chichen Itza, and now I have to live with this forever, as if that's the whole meaning behind it.'' Years ago he told another interviewer, ''The only sources I felt were allowable were American; South American, Mesoamerican or North American. That might mean Eskimos or Peruvians. I wanted to finish off the European impulse.'' Whatever its sources, in its ambition and idiosyncrasy, it is clearly a very eccentric, American vision.

uring the mid-1950's, the National Academy of Sciences raised the question of what should be done with the country's radioactive military waste. The academy proposed various underground sites around the country. Nevada wasn't on the initial list.

But Nevada was where the military had been exploding weapons, where fallout from atomic tests had drifted across mountains and valleys near Heizer's ranch. Nevadans came to learn firsthand what it meant to live in the shadow of the blasts and to distrust what the government said. ''Part of my art,'' Heizer explained when he picked Garden Valley, ''is based on an awareness that we live in a nuclear era. We're probably living at the end of civilization.''

In its remoteness and its intimation of eternal landscapes and ancient monuments, which survive after the societies that built them disappear, ''City'' reflected this sentiment. At the same time, it was inspired, Heizer said, by what he calls the ceremonial city: ''Every old city has the same sort of ceremonial feature, whether it's the Tuileries or St. Peter's or Teotihuacan. The long, stretched-out format of my sculpture is in dialogue with this ancient way of formatting space.''

Heizer also designed ''City'' to blend into the contours of the valley and to act as a kind of bunker or container, open to the sky but dug into the earth, low to the ground (he admires Frank Lloyd Wright's buildings) and, as much as possible, disguised from outside, so that the natural vista would be largely preserved.

The military metaphor of the bunker, with its defensive aura, is hard to miss. When officials from the Department of Energy recently flew over the valley to survey the rail line, they reported briefly mistaking the sculpture for a military project. Years ago, Heizer compared the first part of ''City'' -- a sloped, flat-topped mound with projecting beams that he called Complex One -- to a blast shield. He has since constructed pits and perimeter mounds, turning his work into a sort of airy, roaming fortress made of millions of yards of dirt, so many yards by now that he long ago lost count. ''My interest is in making this thing internalized,'' he said while driving the two of us slowly across the sculpture late one afternoon as the setting sun turned the mountains orange and purple and cast the deepest pits in black shadows. ''It is connected to the environment but not to the landscape. Landscape to me is a planar thing, just a view. Environment is everything down to the ecosystem. Big difference.''

Ten years after Heizer conceived ''City,'' Congress passed the Nuclear Waste Policy Act, which insisted that the Department of Energy find deep geological disposal sites -- and also that the United States must permanently dispose of spent fuel from nuclear reactors, not reuse it, which meant that there would be less dangerous plutonium floating around in the world, but more waste to dispose of. After much political wrangling, three remote Western sites were recommended to President Reagan in 1986, one in eastern Washington State, near Hanford, where the U.S. had already built nuclear facilities for bombs; another in Deaf Smith County, Tex., near a secret plant for nuclear warheads.

The third was Yucca, near Area 51, where the Air Force conducts its so-called black programs, testing its most secret weapons. This is a no-fly zone. Fighters escort out, or shoot down, any plane that strays into the area. The pilot who flew me by helicopter to Heizer's ranch one stormy summer day last year was careful to check in with the Air Force controllers; still he kept one cautious eye on the horizon for lightning, the other out for military jets.

Naturally, no state wanted to store nuclear waste. Nevada, during the mid-1980's, was not in the best negotiating position. Las Vegas was still far from being the boomtown it would become. The state had only one congressman. So it wasn't altogether surprising when in 1987 Congress passed the Nuclear Waste Policy Amendments Act, ordering the Department of Energy to focus exclusively on Yucca.

By then, Heizer had reached an impasse on ''City.'' He finished Complex One in 1974, mostly working by himself, using a paddle-wheel scraper a farmer lent him and following plans drawn up by seismic engineers; then he started on Complexes Two and Three, gargantuan mounds that proved to be vastly more troublesome. Combined, the three Complexes were meant to form a horseshoe, like a stadium open at one end, around a broad pit or plaza. Complex One had protruding, 30-ton, T-shaped and L-shaped columns; Complexes Two and Three were angular dirt mastabas, crystalline shapes, up to a quarter mile long, entailing hundreds of thousands of yards of dirt, one with pointed slabs, like ancient stelae, 70 feet high. ''A lot of money over the years went into simply trying to maintain old, useless equipment,'' Heizer said. ''I never stopped working on the pit and the Complexes, whenever I could afford to. But we're talking crazy optimism here.''

He took commissions to raise money and kept revising the plans for ''City,'' which he had never imagined to be a lifelong undertaking but which was clearly turning out to be one. Some help arrived during the late 1980's when Charlie Wright, the director of the Dia Center for the Arts, visited with potential sponsors and provided cash to shore up what had already started to erode because of harsh weather and construction problems. Dia was founded in 1974 by Philippa de Menil and her husband, Heiner Friedrich, a charismatic but spendthrift German art dealer who sponsored Heizer's Munich sculpture years before. Friedrich considered supporting Heizer at the start of ''City,'' but the two fell out. Then Dia's fortunes briefly collapsed. Wright, with fresh patronage, revived Friedrich's original ambition to back all sorts of grand art projects, like Heizer's.

Then Heizer got sick. In 1995, he mistook pain in his fingers and toes for frostbite because he had been standing in the cold 12 hours a day working on his sculpture. ''I thought I was eternal,'' Heizer told me one evening, relaxing after dinner in his living room, flexing his hands while staring absently at the Science Channel. ''I still do. But back then I took no care of myself. I hadn't seen a doctor or a dentist for 20 years.'' When the pain moved to his back, a medevac helicopter had to speed him to a doctor, who prescribed Tylenol and told him he was drinking and smoking too much. The pain became unbearable. On his way by plane to a hospital in New York, he collapsed and nearly died.

Polyneuropathy was the diagnosis, a nerve disease that progressively caused him to lose much of the use of his hands. His weight plummeted. For a while he couldn't walk, then he had to use crutches. He was in the hospital for months. His recovery was slow. Fed up, he resolved to demolish what he had done so far of ''City.'' Meanwhile, Wright had been succeeded at Dia by Michael Govan, who picked up his plan to aid Heizer in 1996, cultivating more donors, above all the Lannan Foundation. Able to hire workers and rent heavy equipment at last, Heizer went back to work. Although still ailing, he finished the first Complexes by 1999, when I initially visited him -- 27 years after he started. Unbowed, he declared there were another four, even grander, stages to go.

If he'd never gotten to those, he would still have accomplished a feat on a scale not unlike, say, Mount Rushmore, which, along with the cowboy paintings of Charles Russell and Frederic Remington, is just about the only American art Heizer now volunteers to praise. Two Remington cowboy sculptures are on either end of the long table in his living room, and he keeps handy an old book of Russell's paintings of the West. ''I love these artists because they're so precise and faithful,'' he says.

I was flabbergasted when I returned last summer, after several years away, to see what Heizer had accomplished since my earlier visit. I couldn't decipher the work at first, save for a few distinctive shapes. The sculpture melded with the valley. But then Heizer packed me into his truck and drove me to the sculpture, a quarter mile away from the ranch. The additions now dwarf the first phase of the project, making

Complexes One, Two and Three, which are collectively nearly the size of Yankee Stadium, look tiny and precious. The new phases are more pneumatic -- raked dirt formations resembling hills, valleys and mountains. There is a patch of unspoiled sage, like a park, smack in the middle, for flood runoff through the valley (Heizer was thrilled to discover that it actually worked during the recent January storms); and there's now a concrete sculpture, ''45o, 90o, 180o,'' which both evokes ancient Egypt and resembles a board game on the scale of an airport hangar. ''I call it a defracted gestalt,'' Heizer said while slowly steering the truck to the steep precipice of what he calls Alpha mound. ''From the ground you grasp the size but can't make out the shapes -- the opposite of what you sense from the air -- and your perception changes as you move around.''

Heizer occasionally refers to the valley as virgin land; he obsesses about the originality of his conception, about protecting his property and his art from violation by the rail, from developers hunting for underground water, from people trying to sneak in to see the sculpture before it's finished. His project is propelled by anger and resentment and monomania but also by Eros: sculpture as voluptuous, unspoiled and ecstatic, an organic body (one mound from the air, I saw, clearly resembles an erect phallus).

The question, at a time when there's so little talk about government financing for new art of any sort, is whether a country that claims to prize its rugged individualists and its native treasures, both natural and cultural, will care enough to try to avoid ''City'' by running the nuclear train elsewhere -- whether accommodations will be made simply to preserve a sculpture and the equally obscure, awesome valley it occupies.

Obscure, in the art's case, not just because it's physically remote, but also because Heizer has frightened away almost everyone from seeing ''City.'' He's the opposite of Christo and Jeanne-Claude, whose ''Gates,'' to be unveiled this week in Central Park in New York -- another gigantic sculpture project decades in the making -- is ephemeral. Christo and Jeanne-Claude regard the public spectacle of their installation as part of the work itself: the art is a kind of temporary performance. Only when ''City'' is finished -- Heizer predicts it could take another decade to complete the 15 miles of concrete curbs that delineate the mounds and shore up the dirt slopes -- will the public be invited. Meanwhile, as he kept insisting to me while we were bumping down what sufficed for the path through Murphy Gap, anyone trying to show up uninvited will be arrested for trespassing or shot at.

Before I visited him the first time, he interrupted a tirade on the telephone against critics and people he contemptuously called art tourists who want to make the rounds of Earth Art. Then I heard gunshots. When he got back to the phone, he said he'd had to shoot at some coyotes. Then he just picked up the tirade where he left off. In a narrow pass along the drive across the desert this time around, I noticed someone had crudely painted ''Mike's Country Stay Out'' on a rock. The only directional sign for 35 miles was pocked with bullet holes -- used as target practice by ranchers, Heizer told me. It's a message, he speculated. Like him, he said, they just want to be left alone.

Heizer's ranch is a three-hour drive north of two million people in Las Vegas, but it's an hour's drive from almost anyone. His driveway is an unmarked dirt road meandering across several empty valleys and mountain ranges, more than an hour from blacktop. He rarely leaves the ranch these days, and hardly anyone visits except the construction crew. Heizer's Garden Valley is in Lincoln County, which, like half of Nevada, is a place where ranchers run cattle up-country during the spring and summer, down-country during the winter. This is mountainous range. Gold miners used to prospect here; there is still mining for opal and vermiculite.

Heizer and his second wife, Mary Shanahan -- a slender, friendly, brown-haired woman with a wry sense of humor, 21 years his junior, a painter, who was his assistant before they married -- tend a small herd of cattle. They're raising beefalo. They also grow alfalfa. Their house is simple, comfortable, a low two-story building with a big kitchen in front. Heizer fixed it up with hickory floors and fir beams. There's a metal shop, a dog kennel, a bunkhouse for workers to sleep in overnight, pens for cattle and farming equipment scattered along with half-finished sculptures in the yard.

Mary, although she's from Michigan, is a Western classic, soft-spoken and steady. She can birth a calf, make plum jam, change a truck tire, help oversee the complicated accounting on the project, ride herd over construction workers and ranch hands, format the digital images of the sculpture on the computer, reprogram electronics for the testy solar panels and in her spare time retreat to a studio behind Heizer's office and paint abstract pictures of an ethereal calm and Western light. She's in charge of the herd. The plan is to keep expanding it, she said. She and Heizer live pretty much like many small-time ranchers in their elective isolation. He's just the only guy around building the equivalent of the ancient pyramids in his front yard.

Lincoln County is Mormon country, where ranching families go back to the 1800's, people don't like the government telling them what to do and outsiders are regarded with suspicion. It took a while for locals to get to know Heizer, who stayed to himself. His prickliness was always partly calculated: it kept away unwanted busybodies and skeptics while burnishing his reputation as art's ornery outlaw. One evening I discovered Mary and Heizer laughing in the living room. She had come across some old letters that Robert Heizer, Michael's father, had written to various people. They were rants, she said. Like father, like son, I surmised.

When I initially visited Heizer, his pent-up frustration had made him extremely testy with what was then a laconic crew that had no experience constructing anything like ''City.'' The dozen or so men who now work with him -- several of whom trek hundreds of miles each week across the desert to accommodate Heizer's sudden decisions to shift several hundred thousand yards of dirt a few inches this way or that -- profess deep affection. He's a perfectionist; they shrug.

If Heizer, over the years, picked fights and lost allies, insisting, against common sense, he was the first, the only, the best artist around, clearly some people have stuck loyally by him. ''The people who really spend time with him love him,'' says Michael Govan, who, along with Lynne Cooke, Dia's longtime curator, visits maybe three or four times a year to check on the sculpture's progress. ''Never a nickel gets spent on anything that's not necessary,'' Govan adds. ''If Mike weren't managing the construction and we had used outside contractors, it would have cost double, I'm sure. He's honorable.''

The patrons Govan has enlisted -- the Lannan Foundation, the Riggio family and the Brown Foundation, the same Browns, by the way, of the defense contractor Kellogg Brown, which Heizer said was scheming to bump him off -- have stuck with a project that could cost nearly $25 million by the end. ''Mike does things how he wants,'' says J. Patrick Lannan Jr., the foundation's president. ''But it's going to be a monumental gift to culture for generations to come.'' Even Heizer is astonished: ''I told them they're playing with fire. I'm an artist. I don't work with drawings or models. This is a creative process. It's an act of faith on their part.'' When I traveled with Govan and Cooke to ''City'' last summer, Govan mentioned that he had reread Irving Stone's ''Agony and the Ecstasy.''

Later he dug up a passage from the book and e-mailed it to me:

''During all these months the Pope kept insisting that Michelangelo complete his ceiling quickly, quickly! Then one day Julius climbed the ladder unannounced.

'' 'When will it be finished?'

'' 'When I have satisfied myself.'

'' 'Satisfied yourself in what? You have already taken four full years.'

'' 'In the matter of art, Holy Father.'

'' 'It is my pleasure that you finish it in a matter of days.'

'' 'It will be done, Holy Father, when it will be done.' ''

eizer figures that when his own work is done, it will be there for anybody to see for centuries -- that he's building not for today but for the ages. It's a perspective he came by naturally. His father was collaborating on a book about the transport of massive stones in antiquity when he died in 1979, at 64. An obituary by colleagues from the Berkeley anthropology department described Robert Heizer as ''a lone, work-addicted man whose prodigious production required rigid self-discipline.''

Preserved in a file cabinet in Heizer's office is a page from The San Francisco Chronicle, dated Dec. 17, 1941. It's a picture of a slender, youngish Robert holding a box of 350-year-old rusty iron spikes that bound the oaken ribs of a sunken Spanish explorer ship. A 1946 newspaper cartoon of Robert is tucked in the same folder. He's depicted as a bespectacled Indiana Jones in tie and tweed jacket, brandishing a skull before a pile of bones. Some of the mounds in ''City,'' it occurs to me when I see the cartoon, are shaped like bones, and the stelae are a bit like the spikes.

In front of Heizer's house there is also a gigantic perforated sculpture resembling Swiss cheese. During the 1930's, Robert Heizer discovered tiny perforated horns, shamanist objects, left behind by hunter-gatherers who lived beside a prehistoric lake in Nevada.

Heizers have been in or around Nevada since the 1880's. Heizer's grandfather, Olaf, whose own father was chairman of Stanford's physiology department, became the chief geologist for California. He conducted geological surveys in Sumatra and helped map Tennessee, Washington and California. (A family story, Heizer says, is that one of Olaf's horses was used by Eadweard Muybridge for his stop-action photographs.) Ott F. Heizer, Heizer's other grandfather, ran the largest tungsten mining operation in Nevada.

Heizer recalls: ''I was taken out of school by my dad when I was 11 and lived in Mexico City, then later in Paris. I went with him to excavate in Bolivia and Peru. I never finished high school. I was a straight F student anyway. My father admitted to me later that he'd thought I would come to no good. It was tough for my parents because I hated school. I didn't have many friends. I wasn't a sports guy, a team player. The only sport I liked as I grew up was riding motorcycles, and you do that alone.''

At 19, he briefly took a few art classes in San Francisco and started making geometric paintings, then moved to New York in 1966. He supported himself working for slumlords, lugging a compressor over the cobblestone streets in SoHo, hooking up a spray gun and painting a six-story building top to bottom (white in the rooms, brown in the stairwells) in a day. ''It was a hand-to-mouth existence, but I met a lot of artists that way,'' he remembers. ''I met Walter De Maria painting his loft. If you wanted your loft painted for $60 in three hours, I was the guy to call.''

His switch to sculpture in 1967 grew partly out of the geometric paintings he had been doing, which were shaped canvases. These served almost as diagrams for the sculptures he would make in the earth. Much of that first outdoor work was fleeting, almost provisional, the opposite of ''City.'' In 1968, he was included in ''Earthworks,'' the influential group show at Virginia Dwan's gallery, and then in the Whitney Museum's painting annual in 1969, where his contribution wasn't strictly a painting but -- and this helped in a small way to redefine photography -- a huge photograph of a dye painting in the desert.

''When I met him he was 24,'' Dwan recently told me, ''a young 24, sensitive and vulnerable. He has changed over the years, as a result of defending himself from attacks, real or imagined. I was flummoxed by the work. I couldn't figure out this person who seemed to come from outer space, so I asked Walter De Maria, who said, 'Yes, Virginia, he's an original.' So I knew this was someone to be reckoned with.''

For ''Double Negative,'' in 1969, Dwan gave Heizer money, sight unseen. Working partly with Dwan's gallery director, John Weber, Heizer called her from Los Angeles one day to say it was done. A few years later, Dwan bought for Heizer the first parcels of property in Garden Valley, which he chose because the land was cheap, the soil and climate were right and not much of the rest of the valley could be homesteaded. ''When I visited at first Mike was living in a trailer and had a big young Mormon working for him,'' Dwan recalls. The road in and out was a weedy livestock trail, which sometimes got so bad in winter that Heizer would be locked in for months, seeing only a couple of sheep trailers and an occasional pickup truck. Fearful of being robbed, he surrounded the place with cyclone fencing and left only at night to get back before dawn.

Eventually he built himself a house out of cinder-block seconds. When Dwan finally saw the first Complexes, she cried. ''There he is in the middle of nowhere, without an art world to talk to, without a bar where he can go find friends for support, building something much larger than anyone has ever built, knowing he is going to be criticized for grandiosity, and yet going ahead and building what he must. That takes courage.''

Heizer still commuted to New York and Los Angeles, doing commissions, networking. He liked the dinners at Odeon, the parties at Chateau Marmont with movie stars -- until he decided he didn't. ''They're frivolous, I'm not,'' he told me. ''You don't control your own destiny in New York. It's fine if you trust the system and agree to move along the street in an orderly fashion. But you can't carry a weapon to protect yourself, even though it's more dangerous there than here. I find it castrating.''

It has been said that the early works Heizer and Smithson and De Maria and others did outdoors seemed like a fresh start, full of promise. Nancy Holt, the sculptor who was married to Smithson and who used to be close to Heizer, recalled traveling with the two men: ''To go outside into the landscape, that sense of liberation, just crossing the Hudson River, it was glorious. The mass media picked up quicker than the art media what was happening. This was when everyone was seeing the earth from outer space for the first time; 'ecology' was a new word. And when you look at the old photographs of us, you can see the joy in our faces.''

That was then. Should the rail go through, Heizer now claims, he'll dynamite ''City,'' never mind that he is building it to be indestructible for thousands of years, or that the people giving him money aren't likely to fork over another million or so dollars to destroy it and return the desert to its original condition. But with him, it has become all or nothing. Posterity isn't the next generation; it's a millennium. ''Double Negative'' was ''the most incredible sculpture I've ever seen or done,'' Heizer says. ''When I finished I laughed. I knew I'd done it. There was no precedent in the history of mankind.''

And he did not just add his sensibility to radical art movements of the 60's and 70's. As he sees it, he single-handedly, without influence from any other living artist, started a ''revolution.'' ''I'm self-entertaining,'' he declares in another fervid soliloquy. ''My dialogue is with myself.''

The sculptor Richard Serra, Heizer's contemporary, who was an acquaintance of Heizer's during the 60's and whose own work sometimes now rivals Heizer's in size, has said: ''Whoever tells you he dropped from heaven knows the opposite is equally true.'' Serra hasn't seen ''City,'' but he told me that he could imagine ''the work may empower people in ways that don't have to do with scale, in ways that we can't foresee. Heizer's stance is empowering because what artists do is individuate themselves, and this guy has done it to the nth degree.''

Of course, Heizer is not really on his own in the desert, as the nuclear train proves. There was also the MX during the 80's, he reminded me one morning. We were in his kitchen with Gracian Uhalde, his nearest neighbor, who has a ranch about 15 miles away and who works as a contractor on ''City.'' We sat before cups of strong espresso that Heizer likes to serve in glass tumblers at the table his father built for him years ago out of mining timbers scavenged from some abandoned mine shafts in the Golden Gate Range. The MX plan was to crisscross Garden and other nearby valleys -- Coal, Dry Lake, Delamar -- with rail tracks leading to silos for moving around and hiding missiles. (''Peacekeepers,'' as President Reagan called them.) Mary spread an MX map over the kitchen table. It showed the valleys as a checkerboard of rail lines. ''With the MX we won,'' Uhalde said, meaning the government decided not to go through with it. ''Now they're back at it.''

When I found Uhalde working at ''City'' later that same morning, he moseyed over, stomping his feet against the bitter cold, and slid a pinch of chewing tobacco into his cheek. In his early 50's, he has a broad, well-creased face, partly hidden behind a huge white handlebar mustache. His faded overalls matched his light blue eyes. I noticed part of his left pinkie was missing. A calf-roping accident, he told me. Heizer calls him a cowboy, a small-time rancher, which to Heizer is a big compliment.

''People are here because we want to be here, because we're attached to this place,'' Uhalde said. ''You don't come to Lincoln County to make it in the world.'' Like Heizer, he has become outspoken against the Yucca rail plan, which he fears will destroy his cattle's grazing land.

''My grandfather came from the French Pyrenees in the 1880's -- he was Basque -- and at first he emigrated to Idaho as a sheepherder. At some point he was asked to take a herd of about 2,000 to Carson City. He didn't speak a word of English. He told me he had been given a burro and a tent, and when a bear killed the burro, which he needed to carry the tent, he had to leave the tent behind. In return he got 400 sheep, and he settled in Ely, north of here, where there was a Basque community, a kind of subculture.''

Uhalde went on: ''Now we have about 10,000 acres altogether, between the ranch here and one up north, and we farm about 150 acres for hay and have a couple thousand sheep plus 600 cows. We've been around for 100 years. I think the government figured they'd have no resistance in Garden Valley because no one lived here.''

He handed me a palm-size square pamphlet titled ''Atomic Tests in Nevada,'' which was printed in March 1957 by the United States Atomic Energy Commission. Uhalde had been carrying it around lately. It showed cartoons of bowlegged cowboys on the range, watching mushroom clouds rise over the mountains. Allowing that ''fallout can be inconvenient,'' it provides helpful tips like opening windows to avoid shock waves, wearing sunglasses if staring at fireballs and brushing off clothing when covered with radioactive dust.

''I believe it was in 1962,'' Uhalde continued, ''that they did a hydrogen test that looked to me like snow falling in the mountains, the fallout was so bad. My dad never trusted the government. So he and Joe Fallini, his closest neighbor then, who lived 60 miles away, bought a Geiger counter. Deer started showing up with burn patches. Joe's cousin, a little boy, died of leukemia after that. There were dozens of test shots back in those days. We would try to figure out where the pink clouds were heading.

''Then in the late 80's my sister started having symptoms. They thought at first she was epileptic. She was in college at the time. By '92 she was diagnosed with a brain tumor. Around then I got a tumor growing in my bladder. We both applied for downwinders' compensation. We got a total of $50,000.

''Now we say, just leave us alone and take your nuclear glow train through some other valley, along the highway or whatever. Just not here. Here you've got ranching -- small-time, old-style ranching, with the valley as a natural, reusable resource -- coexisting in peace with Mike's project, a cultural monument. The rail will kill all that.''

Heizer joined us in the freezing cold, and he piped in that there were even bigger threats from developers who want to tap the valley's water table. ''The train is just part of the problem,'' he said. ''Developers want to rape this place.'' Railroad Valley, just next to Garden Valley, has oil wells and a refinery in it, Uhalde added.

Is there oil in this valley? I asked.

''God, I hope not,'' he said.

At the end of 2003, the Department of Energy announced the proposed nuclear rail line to Yucca. The Bureau of Land Management, which controls public lands, meaning most of Garden Valley, issued what's called a temporary segregation to reserve the rail route. Next will come an Environmental Impact Statement. When I called to ask about Heizer's fate, Joe Davis, a spokesman for the Department of Energy, said simply that Dia had proposed various ''interesting alternatives we're considering.'' The department plans to issue a draft of what it calls the ''Rail Alignment Environmental Impact Statement'' by late spring or early summer. After that come hearings and another chance for public response before the final E.I.S. is issued and the fate of the rail line is decided sometime early in fiscal year 2006, Davis said.

''We have several laws to comply with,'' Gene Kolkman added. He is field manager for the B.L.M. in nearby Ely and oversees land withdrawal. If the rail line intersects free roaming area for wild horses, that will require modifications because the horses are protected by the Wild Horse and Burro Act. Ranchers must be compensated if the rail cuts off grazing lands and harms their livelihood. ''It's very seldom that a project comes in, especially a controversial project like the Yucca Mountain railroad line, and that it ends up being authorized as it was originally configured,'' Kolkman said.

A former Energy Department consultant on Yucca who is rooting for Heizer's plan to move the route to another valley (and so who asked not to be identified by name) nonetheless defended the selection of Yucca. No site is perfect, he said. But he acknowledged the problem of shipping the waste to Yucca. Spent fuel contains heavy metals, and they aren't called heavy for nothing. They require massive rail containers for transport. Cement for constructing the storage site must also be carried to it, tons of cement, on the scale of Hoover Dam. This is to be one of the largest public work projects ever. The shortest route would skirt Las Vegas, but the more politically feasible path -- and the one mapped by the Department of Energy -- goes from Caliente through the middle of nowhere, which is to say, right through Michael Heizer's front yard. Politics has trumped art, the consultant said, at least for the moment.

Heizer disappeared from the living room where he retreated after dinner one evening and retrieved an old, crumbling children's book. ''Mike Mulligan and His Steam Shovel,'' the 1939 classic by Virginia Lee Burton, is about Mike Mulligan and his red steam shovel, Mary Anne. They quit the big city, frustrated because steam shovels were succeeded by electric and diesel shovels, and they find work in the countryside. In faraway Popperville, they dig a cellar for a new town hall but, in their haste, they forget to leave a way out. They end up entombed in the cellar, Mike as the janitor, Mary Anne as the furnace. Heizer says he loved the story so much as a boy that his mother used to call him Mike Mulligan.

At the sculpture the next morning, while Heizer tinkered in his studio at the ranch, I spotted Jim Hicks hunched beside his truck with his coat collar turned up, cupping his hands against the freezing wind to light a cigarette and looking absently out from the rim above Pits 4 and 5, a nearly sheer drop of 50 feet. Hicks has the chapped lips and weathered face of a cowboy who has spent his life in the great Western outdoors. He has been working on ''City'' for years. He told me he makes the daily commute across the mountains and the desert from Ely, two hours each way, to work 10-hour shifts on this project. ''I can't sleep anyway, so why not drive?'' he said, laughing. Like the other men, he enjoys working for Heizer.

''I've worked on an airport runway and on highways,'' he said, ''where you've got big crews; the bosses flood the projects with equipment, nothing's complicated, you know beforehand the shape and the curve or whatever. This is completely different, 180 degrees.''

How so? I asked.

He nodded toward Beta Mound, an immense, quarter-mile-long construction of dirt with sloping sides, a flat top and a rounded nose. Hicks pointed to the nose. ''I used an 16-foot blade on the grader and most of the time, to get that angle just right on the mound, only about one foot of the blade was scraping the ground.'' He paused. ''I did that. Maybe you wouldn't notice, but somebody will. And that will last hundreds of years.''

When I came across Bill Harmon, who pours concrete for the curbs, he echoed what Hicks said about discovering, in the process of building ''City,'' an American can-do ideal, the fine art of heavy construction. Harmon is from Ruby Valley, 230 miles north, and during the week he lives in a trailer at Uhalde's ranch across the valley with six other guys working on the project, including his two sons, Clint and Bo.

''Mike is demanding,'' he said. ''But that's why things are as good as they are. I've worked in concrete all my life, and I've never had the time or money to do something to the best of my ability. Everything is hurry up. It's about making money. That's the American way. But here we have to produce something that has more to do with accuracy than I've ever been allowed even to imagine. This here is my chance to do the best I can. I travel over 400 miles a week just to be here. And my boys take pride in it, too. When it's finished, I'll be able to say, I had the chance to do that.''

I asked him what he thinks the sculpture is about. ''It's hard to explain,'' he added. ''At the beginning I was lost. I can read a set of blueprints, but I had no idea what we were building. I could not see why we were doing this. I got stuck on the practical stuff -- was this a stadium? Were we going to live in it? And then Mike wanted everything within a sixteenth of an inch, even on a concrete slab that was 78 feet by 240 feet.

''But gradually I got the idea. I can't say exactly what it means now, but I know it has to do with history and with making something that will last. I'm not an artist, but I can tell you I'm real proud to be working on something like this.''

Gracian Uhalde, whom I came across later, echoed that sentiment. ''It takes a while to get used to how Mike does things. But we admire him because he's not afraid to be different. And we're glad for him. It's not too many people in life get to see their dream come true, is it?''

I left at dawn the following day. Roaming antelope and coyote hunting for rabbits had made the dogs bark at night. Now a dozen cats huddled in the cold on the long wood table outside Heizer's kitchen window. Heizer had risen early to say goodbye. He told me he was sleepless, fretting about some of the things he'd said. He didn't want to hurt people's feelings. He wanted to give credit to people like Virginia Dwan, John Weber, Robert Scull and Richard Bellamy, who had supported him, and to Mary and his former wife, Barbara. So much of Heizer's hubris is bravado, I think -- his not having enough people around to vent to, to talk back to him. And in the end the work, which possesses him and drives him and other people crazy, is the only thing that will count -- if it isn't spoiled by the nuclear rail line or if Heizer doesn't blow it up first.

He walked me to my rental car and kicked the tires. ''They're crap,'' he said. ''They'll blow out if you hit a big rock, and then you'll be stuck.'' He reminded me to call when I reached the paved road, so that he'd know I got there.

With that, I drove off, tires crunching in the cold gravel, as the first rays of sun hit the snow on the mountains, casting the valley in a pearly gray pool of winter light.

Home Delivery of The Times from $2.90/week - Act Now!