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.
Michael Heizer was an art-world hero, but now he's learning that you're never far enough away from things  things like mortality and the plans of the U.S. government.