Tourists running roughshod over Utah town : Hordes of mountain bikers seeking thrills on desert trails bring pollution problems to Moab.

A college student pops a reggae tape into the dash of his pickup truck, parked near a lone pinyon tree. Surrounding him on a bluff high above town are hundreds of brightly colored tents, more pickups and more people.

They are here on a warm spring weekend to ride mountain bikes on the famed Slickrock trail, rated “gonzo-abusive” by a local bike shop. The fat-tire wayfarers bring with them food and beer, dogs and toilet paper. The latter lies crumpled in trees, twigs and sand throughout the desert campsites.

Ten years ago, this busted uranium town in southeastern Utah desperately sought tourism. Now, faced with rowdy crowds and a deteriorating landscape, many of Moab’s townspeople wish it weren’t quite so popular. “It’s a circus,” says Bill Hedden, a Grand County councilman. “Hordes of people are hanging off walls, swinging from rocks.”

“We’re overwhelmed,” agrees Russ von Koch, one of only seven recreation planners overseeing 6 million acres for the federal Bureau of Land Management in southern Utah, who says the habitat is being destroyed.

Last year, between 1 million and 2 million visitors came to Moab, population 5,000. Many tour nearby Arches and Canyonlands national parks; others prefer to experience the vast desert on bicycles, in helicopters or in four-wheel- drive vehicles. Most of the springtime revelers camp out on the public land around town.

“During spring break last year, we had riots,” Von Koch says. “There was a lot of underage drinking, with up to 500 people in one small site, starting bonfires, burning trees. Now we’re starting to regulate it more. We want to keep the number of campers per site below critical party mass.”

But the agency can barely keep up. Despite 55 new campsites with toilets, there’s never enough for the tourists, whose numbers increased 34% last year. Along the Colorado River, cottonwood groves yield the stench of human waste and garbage accumulated over a season of weekends.

In the old days, environmentalists worried about cows, strip mines and large dams. Now, says Scott Groene of the Southern Utah Wilderness Alliance, they have a new enemy, and it’s a moving target.

“At first we thought, great, tourism; it’s clean,” Groene says. “But now it’s out of control. The bighorn sheep barely survived the uranium boom. Now the mountain bikers might finish them off.”

Many of Moab’s visitors have little knowledge of treading lightly in desert ecosystems, officials say. Pollution and threats to wildlife are just a part of the problem.

Perhaps of greatest concern to scientists is the health of the area’s soils, already stressed from limited nutrients and the dry climate. Known as cryptobiotic soil, the desert’s dense, crusty surface helps prevent erosion, absorb scarce water and process nitrogen critical for plants.

Tire treads and footprints compact and kill the black soil, which is made up of lichens, fungi and microbial bacteria. “Where these soils are heavily trampled,” says Jayne Belnap, a Moab-based research ecologist for the National Park Service and the National Biological Survey, “the ecosystem literally shuts down.”

Partly in response to research by Belnap and others, the National Park Service and BLM are trying to educate visitors to stay on trails and roads. A national mountain bike patrol, the country’s first, is slated to roam the Moab area in the fall.

The town and county also are trying to soften the impact of the sporting masses. Moab’s tourism bureau plans to insert a list of environmental guidelines in every information packet it sends this summer. And the county council got so fed up with the constant buzz of scenic helicopters that it issued a moratorium on new licenses in November. Councilman Hedden says he would like to eliminate heli-biking, in which helicopters drop off bikers at remote, pristine locations.

Grand County also hopes it can recoup some of the costs of servicing the endless stream of desert adventurers. Last year, the sheriff’s office performed more search and rescue operations on its small budget than the rest of Utah combined. In an unusual arrangement, the county and the BLM are considering charging a joint fee for people who want to camp or engage in other recreation near the Slickrock trail.

“We need to look at ways for visitors to help cover the costs of protecting the resource and maintaining it,” Von Koch says.