As the lowering sun suffused the castle-like spires of Family Butte, we picked our way across the sagebrush-and-piñon-dotted "Sinbad Country" of south-central Utah, 7,000 feet high in the heart of the San Rafael Swell. The day before, we’d hiked through the San Rafael Reef, a 1,500-foot wall of upthrust flatiron composed of towering, tilted slabs of multicolored sandstone. Now red rock was beginning to reappear, scores of sloping pediments capped by cliffs, swarming mesas standing on striated footings like layer cakes.

As I ogled this tableau, something began to compete for my attention. At first it sounded like a fly, then a lawnmower, then a chainsaw. Soon it became visible: a yellow off-road motorcycle, its helmetless, sunglassed, goateed rider smoking a cigarette as he closed in on me from behind.

The bike zoomed past and disappeared downhill into the canyon. When we reached the bottom, I could still hear the whining engine working its way through the willows and cottonwoods along Muddy Creek. Soon it reappeared, cutting back cross-country toward me through the riparian vegetation on the valley floor. A hundred yards away, my companions were settling down for the night, but the peaceful stillness of the canyon was shattered as the rider went about the business of having fun.

The San Rafael Swell’s dome-shaped uplift is the northernmost example of "canyon country." As such, it is easily accessible to the burgeoning population of the Wasatch Front via Interstate Highway 70, which runs east-west through the middle of the region. This road was responsible for my own introduction to the 1,500-square-mile area when, en route from California to Colorado one Labor Day, I found myself in an astonishing landscape of shining mesas and plunging canyons, with violet shadows accentuating the outlines of vermilion, burgundy, and tapioca-colored sandstone carved into otherworldly shapes by eons of erosion. Later, when I happened to fly over the area, I realized how it had gotten its name: Stretching west from the Green River was an enormous, egg-shaped blister, red around the edges, which appeared to have been scoured and swept by some extraterrestrial broom.

Our group of 11 desert-hiking enthusiasts assembled at Justensen Flats, a high meadow area just off I-70. This also turned out to be a convenient meeting place for all-terrain vehicles (ATVs), whose riders use it as a jumping-off point for the northern San Rafael Swell. As I was waiting for my companions, four ATVs came roaring out of the backcountry, piloted by two fortyish couples who had piled coolers and gear on their rear racks for a day in the boondocks. Loading the $6,000 vehicles into an enormous panel van, they told me that it was possible to make a 50-mile loop from the point where we stood.

ATVs are four-wheel dirt bikes with knobby tires, compact engines, and indestructible frames. Easier to ride than motorcycles but less confining than jeeps, trucks, or sport-utility vehicles, they’re engineered to power over or through everything from mud bogs to boulder fields to brush-shrouded streambeds. Whereas a motorcycle’s wheels disturb one acre of topsoil in 20 miles of travel, an ATV churns up six. A subcategory of the vast and proliferating horde of off-road vehicles (ORVs), they appeared on the market in 1982, superseding the three-wheel version that was banned because of its high rate of rollovers and injuries.

ORV registration in Utah has quadrupled to 80,000 over the past dozen years, and the state is now second to California in ORV use. Even though associated fees contribute more than a million dollars to state coffers, only half of the protected areas in the San Rafael Swell have signs directing drivers onto sanctioned routes or informing them that off-trail riding is illegal. Since only one Bureau of Land Management ranger patrols the 2.5 million acres, compliance is largely voluntary.

"ATVs aren’t going to go away," veteran rider Mark Williams, president of the SouthEastern Utah Off-Highway Vehicle Club, told me. "We’re gaining more registrations every year. There’s no way you can lock up [the Swell] and keep all the people out—you’d have to have an army. That’s why, if they closed the roads into Sids Mountain, I think we’d ride ’em anyway. That area is just too vast, and the federal government doesn’t have the manpower."

"A lot of our club members are in their 50s and 60s," says Williams, who is 62 himself. "One is in his 80s; others are in their 30s and 40s. Most of us drive SUVs, but it’s much easier to use an ATV on rough dirt roads to see the country and hunt deer and elk. If we were all great hikers, maybe that would be the way to see the country, but I’ve got a heart condition so there’s no way I can hike. Everybody ought to be able to see the deep canyons, though—Sids Mountain, Coal Wash, the Devil’s Racetrack, and Eagle Canyon are the best-looking part of the San Rafael Swell. What good is a wilderness if nobody sees it?"

Our hiking group was intent on seeing the Swell, but without noisy machines. We ranged in experience and ability from Steve Thaw—one of 55 people to have climbed every major mountain in the Sierra Nevada—to those (like me) who were more gravitationally challenged. Our leader, Dave Holten, showed up in a T-shirt proclaiming "Age and treachery will always overcome youth and skill." Holten, a 72-year-old retired engineer from Sparks, Nevada, has been backpacking since he was 12. Every spring he leads a camping and hiking sojourn to southern Utah, always including proposed wilderness areas in the itinerary. This year the first hike took us into the Sids Mountain Wilderness Study Area, stretching north from I-70 to the Little Grand Canyon of the San Rafael River, and including the state’s densest concentration of desert bighorn sheep.

Of the seven wilderness study areas the BLM identified in the Swell in 1980, none has yet been officially preserved. Utah politicians generally treat wilderness designation as akin to domestic terrorism, and the state’s Republican congressional representatives have repeatedly tried to pass token wilderness bills that would actually eliminate most wilderness areas. (Luckily, they have repeatedly been stymied by the Southern Utah Wilderness Alliance, the Sierra Club, and others.) The latest tack is from Utah’s Republican governor, Mike Leavitt. Having complained long and loud about monuments created by President Bill Clinton, Leavitt now proposes that President George W. Bush declare the San Rafael Swell a national monument. Mining and drilling would be prohibited (they are largely obsolete in the Swell anyway), but decisions about vehicle access would be left to the BLM, based on local (read: anti-wilderness) input.

We got a taste of the local perspective as we approached the Sids Mountain Wilderness Study Area. On the trail toward the Devil’s Racetrack we encountered a BLM kiosk papered with an array of messages posted by local ATV users, including Mark Williams’s outfit:

The Sage Riders and the SouthEastern Utah Off-Highway Vehicle Club ask that you obey the law and stay out of closed areas. The Southern Utah Wilderness Alliance (SUWA) and the Sierra Club (SC) are watching this area, taking pictures and documenting any illegal intrusions. . . . We ask that you obey all closures and that you confine your travel to the approved trails, routes, and roads. . . . By putting tracks in areas that are closed you are handing SUWA & SC the ammunition that they need.

None of us agrees with all of the WSA [wilderness study area] boundaries, the BLM’s failure to acknowledge the many roads within those boundaries, the closure of most of those roads, or the selfish acts of SUWA. But, we do agree that the best way to protect access to the roads and trails that remain open is to obey the law. Please don’t sacrifice our children’s access for tomorrow by selfishly breaking the law today.

This would have been more encouraging were it not for the fact that the "approved" trail in question led into a wilderness study area, which is supposed to be treated as wilderness until Congress decides whether it should be protected. Back in 1991 the BLM had recommended closing 10 percent (more than 150,000 acres) of the Swell to ORVs, but when angry letters poured in from riders, the plan was put on hold. It took a lawsuit by the Southern Utah Wilderness Alliance, the Sierra Club, and six other environmental groups to force the BLM to begin controlling ORV damage. As a result of the lawsuit, the agency did order an emergency closure of the seven wilderness study areas in the Swell—except, that is, for four routes in the Sids Mountain area, including the one we were on.

The consequences lay before us. Tire tracks repeatedly strayed from the path, making forays into adjacent areas in spite of the signs lining the trail. Some signs had been pulled out or run over, as had several plants. In many places, cryptobiotic soil—the organic microbial layer that binds the desert surface, protecting it from erosion—had been overrun and obliterated. Nevertheless, the BLM’s "preferred alternative" is to leave the Devil’s Racetrack trail open to mechanized vehicles.

A mile beyond the trailhead, the magic of the Swell reasserted itself. As we reached the edge of Bullock Draw, the red earth suddenly fell away to a bright green band at the bottom of the canyon. Beyond it, formidable landforms with fanciful names—Devil’s Monument, Slipper Arch, Twin Priests—decorated the horizon. Departing the trail by a wooden fence that had been erected to exclude ORVs, we headed overland toward the Blocks, buttes as square and abrupt as their name.

Making our way across a now-trailless landscape, it occurred to me that the scene at my feet was not unlike the one I’d glimpsed from six miles in the air. Everything we saw—windblown dirt, sun-blasted rock, twisted piñon limbs—was weathered and ancient.

We ate lunch above the east fork of Coal Wash before dropping into the deep gorge via a tricky cleft in the cliff. When we reached the arroyo floor, we got an entirely new perspective: Instead of gazing out at endless, apparitional horizons, we now stared up at colossal cliffs intersecting the azure sky, the crimson cast of the cliffs creating a harmonious backdrop for emerald cottonwood leaves. Suddenly we were in a riparian environment, full of luxuriant stream-fed foliage, crystal-clear pools with water bubbling up from the bottom, and tiny waterfalls trickling over the rocks, bound for the San Rafael River and ultimately the Colorado. Despite the fact that it "would allow for continued loss of riparian vegetation, breakdown of streambanks, and subsequent erosion problems," the BLM plan for the Swell recommends leaving ten miles of such riparian corridors open to ORVs.

This area would be permanently protected by America’s Red Rock Wilderness Act—a Sierra Club–supported proposal that, in aiming to preserve 9 million acres of pristine landscape (a million of them in the San Rafael Swell), has attracted 163 cosponsors in the House and 17 in the Senate. Unfortunately, for the past two years the chair of the House Resources Committee—controlling all public-lands hearings and legislation—has been Utah representative Jim Hansen (R), who favored dismembering every national monument created by the Clinton administration, starting with Grand Staircase–Escalante in southeastern Utah. Hansen retired last year, but given the Republican leadership in the House and Senate, passing the Red Rock Wilderness Act remains a long-term goal.

We completed several more hikes over the following week, making a circuit of the cream-and-strawberry ramparts of Temple Mountain, still scarred by the pits and derricks of the uranium era. Ascending into the Crack Canyon Wilderness Study Area, we got a bird’s-eye view of Hidden Splendor, the legendary mine that prospector Vernon J. Pick sold in 1954 for $9 million to the Atlas Corporation, which abandoned it three years later after extracting a fraction of the anticipated uranium. To get there, we had to negotiate Wayne’s Wiggle—a near-vertical tunnel that ejected us onto a high, rocky plateau, from which we surveyed a good-size portion of the southern Swell, from Factory Butte to Dirty Devil. We made our way along a vertiginous precipice, the vast drainage of Muddy Creek spread below us like some scarlet kingdom.

"What good is a wilderness if nobody sees it?" Williams had asked. But according to the 1964 Wilderness Act, wilderness, in addition to being "untrammeled by man," is supposed to contain "outstanding opportunities for solitude or a primitive and unconfined type of recreation." Though ATV use is in some ways primitive and certainly unconfined, I doubt that’s what the framers of the act had in mind. More than 94 percent of BLM land in Utah is already available for ORV use, and 85 percent of the area in America’s Red Rock Wilderness Act lies within two miles of a road. My middle-aged mates and I had just spent a week in it, and the view was just fine. Driving to see wilderness, however, is like driving to see a mirage: When you get there you find it’s gone.