We were made to walk. Our species excels at putting one foot in front of another over great distances, and since we evolved into walkers, poets and philosophers have used the act of walking to sort through their ideas, lovers to court, pilgrims to seek redemption, and mountaineers to do a lot of complicated things we can talk about later. But now most of us live in a world where the desire to walk is subdued or thwarted by design—by the layout of suburbs, by the speedup of expectations. And when we stop navigating the world by the strength and at the speed of our bodies, our bodies themselves start to become obsolete. I know people who have walked the length of a mountain range, but I come across a lot more people who believe that traveling farther than a Major League pro can hit a baseball requires mechanical intervention. Cars often become prosthetic devices for those handicapped only in their imagination of the world and their abilities to traverse it.

In ecological terms, walking is an indicator species for various kinds of freedoms and pleasures: free time, free and alluring space. Walking still covers the ground between cars and buildings, between the driveway and the house, but as a cultural activity, as a pleasure, as travel, it is fading, and with it goes an ancient and profound relationship between body, world, and imagination.

If walking is an endangered species, the gym has become a kind of wildlife preserve for bodily exertion. That muscles have become status symbols signifies that most jobs now no longer call upon physical strength; like suntans, muscles have become an aesthetic of the obsolete. Now that machines pump our water, for instance, we go to other machines to engage in the act of pumping, not for the sake of water but for the sake of our own bodies. Likewise, what used to be a sack of onions or a barrel of beer to be hoisted is now a metal ingot. So the body that used to have the status of a work animal now has the status of a pet. It does not provide real transport or real labor, as a horse might have; instead it is exercised as one might walk a dog.

The first exercise machine, in fact, was designed as a particularly tedious form of Sisyphean punishment. The treadmill was originally used in a British house of corrections in 1818 to rationalize prisoners' psyches. As one 19th-century penal expert observed, “It is its monotonous steadiness and not its severity, which constitutes its terror.” It is still the most perverse of all the devices in the gym. Perverse, because I can understand simulating farm labor, since the activities of rural life are not often available, and I can understand climbing in a climbing gym when the weather is foul or when it is dark, but simulating walking suggests that space itself has disappeared. The treadmill is a corollary to suburban sprawl: a device with which to go nowhere in places where there is now nowhere to go.

I had gone everywhere in pursuit of the history of walking, from garden mazes to Catholic pilgrimages to Parisian boulevards and Sierra passes, but I was sure there must be some place that summed up all that history, some place to track down its future. I tried to convince myself it was England's Peak District, but finally it hit me: Las Vegas.

Often portrayed as exceptional, Vegas is instead merely extreme, an extreme version of America, an unrestrained attempt to satisfy public desire. Nowhere did the car triumph more spectacularly than along the neon-splashed asphalt of Las Vegas. Few remember that when the place began to flourish more than half a century ago, people walked everywhere. The train deposited visitors on Fremont Street, where they could stroll to and from a number of nearby casinos. But that was before bigger and more fantastic resort-casinos began to migrate south out Highway 91, toward Los Angeles. Fremont Street began its long decline, and Highway 91 became the Strip, like automotive strips everywhere, only more so—more effervescently, seductively, gargantuanly so. Then, in the last several years, something utterly unexpected happened. This Strip of Strips started luring pedestrians.

Like those islands where an introduced species reproduces so successfully that its teeming hordes devastate their surroundings and starve en masse, the Strip has attracted so many cars that its eight lanes of traffic are now in almost continual gridlock. Now that the once-scattered casinos have grown together into a boulevard of fantasies and lures, tourists can park in one casino's behemoth parking lot and wander the Strip on foot for days, and they do, by the millions—more than 34 million a year, upward of 200,000 at once on the busiest weekends. Even in August, when the temperature hovers around 100 degrees after dark, I have seen the throngs streaming slowly up and down, though not more slowly than the cars.

Years ago, after falling asleep in the black velvet of a desert night in a car heading from California to an antinuclear gathering at the Nevada Test Site, I woke up when we came to a halt at a traffic light on Las Vegas Boulevard. The sky was a jungle of neon vines and flowers and words bubbling and exploding. I still remember the shock of that spectacle, heavenly and hellish in equal measure.

That bright neon was only a mile or two from the inky desert then. Even now, the east-west avenues of Las Vegas run straight as latitude lines, and looking west down most of them you can see the 13-mile-long escarpment of Red Rocks and, behind that ruddy sandstone wall, the 8,500-foot-high gray peaks of the Spring Range. Of course, despite mountain ranges on three sides—the Spring Range to the west, the Sheep Mountains to the north, and the Black Mountains to the east—and glorious desert light, this amnesiac boomtown has never been about nature appreciation. Not in 1900, when the tiny railroad stop had a population of five. And not now, swollen with 1.25 million residents. Between the glamorous Strip and the desert now lies a colossal sprawl of trailer parks, golf courses, gated communities, and generic subdivisions.

I had planned to walk from the Strip all the way to the desert, but the desert was miles farther away than I remembered. When I telephoned the local cartographic company for clues, I was told that the city was growing so fast that they had to put out a new map every month. They recommended some of the shortest routes between the Strip and the city edge, but I drove them and saw they were terrifying places for a solitary walker—miles of warehouses, light industrial sites, and vacant lots in which only cars and hoboes stirred.

It was too late—by a matter of years—to walk all the way out of Las Vegas, but by beginning from the city's pedestrian heart I could at least trace its main artery. And so, on a room-temperature December morning, I stepped out of my friend Pat's van onto Fremont Street in downtown Las Vegas, and he set off to spend the day climbing in Red Rock Canyon.

I carried no water on my hike, no backpack. As Pat's van disappeared into the traffic, I just started walking, making a little circuit of the old part of town before heading down Las Vegas Boulevard toward the new.

The railroad-era glitter of Fremont Street has suffered by comparison with the Strip's new fantasy environments, so it has been redesigned as a sort of cyber-arcade. In its shade pedestrians were milling around freely. Up above the resurfaced street is a high, arched roof on which light shows play at night, so that what was once the night sky itself is now a kind of giant television screen. It's a sad, half-abandoned place in daylight, and it didn't take long for me to leave it for Las Vegas Boulevard, which would, in due time, become the Strip.

Here the Boulevard was a skid row of motels, shabby apartments, sad souvenir stands, pornography stores, and pawn shops. I peeled off a sweater and headed south in my old hiking boots worn down from too much concrete. A homeless man in a brown blanket watched me walk by as I watched an Asian couple across the street coming out of one of the Strip's tiny wedding chapels, him in a dark suit, her in a chalk-white dress, so impersonally perfect they could have fallen off a colossal wedding cake. Farther on I came to the old El Rancho hotel, burned out and boarded up. The early casinos romanticized the desert West—the Dunes, the Sands, the Sahara, the Desert Inn, the Golden Nugget—but more recent additions to the Strip have thrown regional pride to the winds and summoned up any place else, the less like the Mojave the better. The Sands was just replaced by the Venetian, complete with canals.

Just as hikers are people who walk around in wildernesses they don't live in, tourists are people who walk around in cities they don't live in. They now stroll Vegas as though they were going from church to church in Rome—walk it with the slow pace and preoccupied expression of the bemused and dazzled. The bride and groom I had seen coming out of the wedding chapel showed up again a mile or so south, she with a delicate quilted jacket over her wedding dress, teetering cautiously on spike heels. Under the tired pavilion in front of the Stardust, an old French couple asked me for directions to the Mirage. I watched them amble away toward the new nostalgic fantasyland at the Strip's heart and followed them south against a tide of cowboys and cowgirls streaming north from the National Rodeo finals at an exhibition hall near the UNLV campus.

At the Frontier casino I walked through the door and stepped inside the usual supernova of dizzily patterned carpet, jingling slots, flashing lights, mirrors, staff moving briskly and visitors milling slowly in the eerie indoor twilight. Casinos are made to get lost in, with their windowless expanses full of banks of slot machines tempting visitors into opening their wallets before they find the well-concealed exits. Many of them have installed “people movers,” those motorized sidewalks they have in airports, but the only ones I saw were inward-bound. You apparently have to hike out under your own power.

Wandering and gambling have several things in common: They are both activities in which anticipation can be more delicious than arrival, desire more certain than satisfaction. To put one foot in front of another or one's cards on the table is to entertain chance, but gambling has become a highly predictable science for the casinos, and they and the law enforcement officials of Las Vegas are trying to control the odds on walking down the Strip too. Las Vegas Boulevard is exposed to the weather, open to its surroundings, a public space in which those glorious freedoms granted by the First Amendment can be exercised, but a mighty effort is being made to take them away. The Strip's sidewalks are currently the province of leafleteers advertising a veritable army of “private dancers” and “escort services,” because the ACLU fought to overturn a county ordinance against “off-premises canvassing,” but police officers can still detain people for “blocking the sidewalk.” Some casinos have started policing the sidewalks themselves. The Mirage had even erected a little sign on one of its lawns, a sign since ruled illegal by a federal judge: “This sidewalk is the private property of the Mirage Casino Hotel upon which an easement has been granted to facilitate pedestrian movement. Anyone found loitering or otherwise impeding pedestrian movement is subject to arrest for trespass.”

At noon I was already hot and weary from the four or so miles I'd traveled from Fremont Street. It was a warm day, and the air was stale with exhaust. Distance is deceptive on the Strip. The major intersections are about a mile apart, and the new casinos with their 20- or 30-story hotel towers look closer than they are, and their scale makes walking seem slower and more futile.

Nature of a virtual sort reasserts itself at Treasure Island, the first of the new theme-park casinos a hiker reaches from the north, and one of the most fantastic. It resembles a hotel-resort version of Disneyland's Pirates of the Caribbean ride, with a facade of fake rock behind a lagoon full of palm trees and pirate ships. Next door, the Mirage's volcano erupts every 15 minutes after dark. When the volcano began its rumblings in 1993, Treasure Island upstaged it with a full-fledged pirate battle that culminates in a sinking ship, but the battle only takes place a few times a day. Both casinos boast giant fountains, but the vast sheets of water fronting the Mirage and Treasure Island are dwarfed by the eight-acre lake at the Bellagio casino, across Flamingo Road from Caesars Palace. Most of it is the same Colorado River water that rafters bounce on and environmentalists hope to undam upstream.

Around these triumphal cascades, Las Vegas is replacing its neon-go-go Americana futurama vision with Europe, or at least a fun pop-culture version of it. The fountains, the volcano, the pillars, the manicured cypresses of Caesars Palace all say old Europe—the Europe of parks, gardens, plazas, arcades, and streets in which people once walked for pleasure. As a Vegas promoter might say, the garden is making a comeback, crossbred with the boulevard, and with that new hybrid comes pedestrian life.

Though walking may be an inadvertent side-effect of gambling—after all, the casino fronts weren't built out of public-spiritedness, but as bait—the heart of the Strip is now filled with pedestrians. There are even overpasses for walkers on the Strip to eliminate the messy intersection of people and cars—handsome bridges giving some of the best views around. I walked on the bridge over Flamingo Road between Bellagio and Caesars and was rewarded with the best view yet of Red Rocks and the desert to the west.

From another bridge, the one from Bellagio to Bally's, I could see—Paris! There, rising out of the dusty soil of the Mojave like an urbane mirage, was the Eiffel Tower, aggressively straddling a stumpy Hôtel de Ville with the Arc de Triomphe jostling it in an antigeographic jumble of architectural greatest hits. Just down the road from Paris-Las Vegas was New York- New York, the Japanese-style Imperial Palace sat nearby, and a much older version of San Francisco—the Barbary Coast—faced Caesars' populist, or just plain pop, version of ancient Rome. I ate a late lunch in New York and drank three pints of water to replenish what had evaporated from me in the desert aridity of my trek through the wilderness of themes.

Like the Paris Casino, New York-New York is itself a sort of greatest-hits compilation, with the Statue of Liberty fronting a bouquet of skyscrapers and, inside, a funny little maze of streets made to look like various Manhattan neighborhoods, complete with graffiti, air conditioners jutting out third-floor windows, street signs, and shops—of which only the souvenir and food shops are real, as I found when I foolishly lunged for a bookstore. But New York-New York is free of the dangers and possibilities of real urban life; it is a walk-through souvenir, no longer pocket-size and portable but there to remind visitors, as souvenirs do, of a few reassuringly pleasant aspects of a complicated place. Like a fake volcano and unlike a real city, it isn't, so to speak, a gamble.

Outside New York, a young woman from Hong Kong asked me to take a picture of her with the Statue of Liberty behind her and then another picture with the huge golden MGM lion across the street, and she looked ecstatic in both shots. Fat people and thin people, people in baggy shorts and in sleek dresses, a few children and a lot of old people streamed around us, and I handed the camera back and continued south with the crowd to the Luxor, whose pyramid shape and sphinx say ancient Egypt, but whose shiny glass shouts technology. The newlyweds I had seen twice before were there in the entryway: She had laid aside her coat and purse to pose for his camera in front of one of the mock-Egyptian statues.

I wondered about them—about why they had chosen to spend the first hours of their honeymoon strolling the Strip, about what past they brought to this global fantasy in the Nevada desert. Who is to say that, merely because a tourist is visiting Las Vegas, he or she does not also vacation in the Lake District, or live the life of a Parisian boulevardier? That the Guatemalan woman I saw handing out helicopter-ride coupons might not walk the stations of the cross in her church, that the bride and groom might not be Japanese climbers of Mount Fuji or southern Californian executives with treadmills at home? The most attractive thing about this pedestrian oasis in the middle of suburban sprawl in the middle of a great desert expanse is that it hints at the breadth of walking's tradition—not in its fake Rome or its faux Tokyo, but in its Italian and Japanese tourists. Las Vegas suggests that the thirst for places, for cities and gardens and wildernesses, is unslaked, that people will still seek out the experience of wandering about in the open air to examine the architecture, the spectacles, and the stuff for sale, and will still hanker after surprises and strangers.

Vegas is not an anomaly, but an intensification of mainstream culture, and walking will survive outside that mainstream and sometimes reenter it. When strips and suburbs like Vegas's were being developed in the decades after World War II, Martin Luther King Jr. was studying Gandhi and reinventing Christian pilgrimage as something politically powerful at one edge of this continent, while at the other Gary Snyder was studying walking meditation and going climbing in the Sierra Nevada. And today, walking traditions are being maintained by a global resurgence of pilgrimages, by a surge of pedestrian-rights groups in cities, and by mountaineers and hikers outside them.

When the twilight outside finally matched the eternal twilight inside the casinos, I called it a hike and went to meet up with Pat. “This place is a maze,” he immediately grumbled (confirming my thoughts about the place) wwhen he turned up a little late at our rendezvous spot in Caesars Forum, the arcade attached to the casino. The Forum's arched ceiling is painted to look like the sky, and recessed lighting changes from day to twilight and back every 20 minutes or so. Its curving “streets” are full of distractions: the stores packed with clothes, perfumes, toys, knickknacks, a fountain with a backing glass wall full of tropical fish, the famous fountain of nubile gods and goddesses who periodically “come to life” in a simulated thunderstorm with laser lightning snaking across the skylike dome. Caesars Forum is constantly thronged, as much for its simulations of live and natural phenomena as for its shopping.

We found Pat's van, and he drove back toward Red Rocks on Charleston Boulevard, out one of the westbound streets I'd been looking down all day. As we entered the desert, the streetlights grew progressively dimmer and farther apart, but the sky never lost its star-obscuring glow.

In defense of his adopted hometown, the art critic Dave Hickey, who lives in Las Vegas, once wrote, “Just the other day, I took down my grandfather's Cicero and read for nearly an hour without anyone breaking down my door and forcing me to listen to Wayne Newton.” No one is forcing tens of thousands of people to wander the Strip either, but they're a lot more likely to do that than to head 20 miles west of it to the 307-square-mile Red Rock Canyon National Conservation Area, whose spires and buttresses are far taller and more spectacular than any casino. Many people only drive through or step out long enough to take a photograph, unwilling to surrender to the slower pace. Walk away from your car, however, and you'll find that twilight comes only once a day, and wildlife does as it pleases. It's a place with nothing to structure one's pleasure but a few trails, bolts on the rocks, maps, and an entrenched tradition of nature-worship. Nothing happens here most of the time, except seasons, light, and the slow parade of your own thoughts.

I think that the time one spends musing takes place in a kind of meadowlands of the imagination, a part of the imagination that has not yet been plowed, developed, or put to any immediately practical use. Environmentalists are always arguing that those butterflies, those grasslands, those watershed woodlands have an utterly necessary function in the grand scheme of things, even if they don't produce a market crop. The same is true of the meadowlands of the imagination. The fight for free space—for wilderness and for public space—should be accompanied by a fight for free time to spend in that space, wandering, for it is in this wandering afoot that one best reaches the wildlands of the imagination. Vegas has not yet decided whether to pave over or encourage that space; fake volcanoes and long boulevards do a little of both.

That night we slept out by the quarry near Red Rocks, in an unofficial campground with figures silhouetted against the small fires burning here and there under the starry sky and the glow of Vegas visible over the hill. In the morning, we met up with Pat's climbing partner for the day, a young guide named Paul who often drives out here from Utah. Paul led us along a trail, snaking up and down across small arroyos and a dry streambed, past gorgeous foliage, junipers with desert mistletoe, tiny-leafed desert oaks, yuccas, manzanitas, and an occasional barrel cactus—all stunted by the rocky soil and lack of rain into small, twisted, and elegantly spaced plantings that, with the large rocks strewn so elegantly here and there, make Red Rock Canyon look like a giant Japanese garden. When I turned back to look at Las Vegas, as I had so often looked toward Red Rocks the day before, Paul said, “Don't look back,” and then, “I'm waiting for them to put a dome over it so it can always be night there.” But I stared, amazed by how thick the city's smog was, a brown cloud with only a few building spires murkily visible within it. That the wilderness could be seen clearly from the city but not the other way round seemed as neat an allegory as I'd ever met. As though one could look back from the future to the past but not forward from this ancient geologic and natural place to a future shrouded in trouble, contradictions, and fumes.

Paul led us off the trail into the brush that climbed narrow Juniper Canyon, and I managed to heave myself up the various shelves where the rock was sometimes striped red and beige in thin layers, sometimes covered with spots the size of coins, until we were at the foot of the climbing route Olive Oil. According to Pat's battered American Alpine Club Climber's Guide, “This route ascends obvious crack systems for 700 feet up the south side of the Rose Tower.” I lounged about and watched Pat and Paul climb up the first few hundred feet with ease, and watched scurrying mice who were less dramatic than the white tigers and dolphins of the Mirage, but livelier. Afterward, as the day wore on, I wandered along the few trails to the clear rushing water of Pine Creek, explored another canyon, and turned back to watch the shadows over the hills grow longer and the light thicker and more golden, as though air could turn to honey, honey that would dissolve into the returning night.

Leaving Las Vegas