U.S. Forest Service managers in parts of Montana and Idaho are working to ban mountain bikes on landscapes that some day could merit wilderness designation, a move that isn't sitting well with the International Mountain Bicycling Association. Over at the National Park Service, meanwhile, officials have no intention of letting mountain bikers access lands eligible for wilderness designation.

“Existing lands that have been determined to be eligible for wilderness, they should not be considered for potential mountain bike trails at this point," says Garry Oye, the Park Service's wilderness and recreation chief. "We wouldn’t want to authorize a use if we’ve already determined that the lands should be considered for wilderness. We wouldn’t want to allow a use that would compromise that future designation. That’s consistent with our policies.”

Since 2005 at least IMBA has been working to expand mountain bike use in national parks. That year saw the organization and the Park Service sign off on a Memorandum of Understanding calling for a five-year pilot program that would explore mountain bike possibilities in the National Park System via pilot projects in three parks. Initially that MOU was aimed at opening more dirt roads and administrative roads to the cyclists, but not long afterward IMBA officials began talking of the need for single-track routes in the parks.

While those efforts led to a study in Big Bend National Park to create a "shared use" trail, one designed primarily with mountain bikers in mind, IMBA officials began working to change Park Service regulations that must be negotiated before a park superintendent can open park terrain beyond developed areas to mountain bikes. As the clock was running out on the Bush administration the Interior Department published a proposed rule to "streamline" the regulatory landscape regarding mountain bikes in national parks, but it quickly drew criticism from groups that feared how much Park Service landscape its passage could affect.

There are places for mountain bikers to ride in the National Park System. Hundreds of miles of mountain biking opportunities exist in the parks, ranging from the classic, 100-mile-long White Rim Trail in Canyonlands National Park to routes through the woods at Mammoth Cave National Park, the carriage paths in Acadia National Park, and even the rail trails in Cape Cod National Seashore. In all, more than 40 national park units off mountain biking opportunities in some form.

But not all public land landscapes are open to mountain bikers. This past Sunday's New York Times ran a story about Forest Service efforts to institute regulations that would ban mountain bikers from hundreds or even thousands of miles of trail that weave through lands that one day could be designated as official wilderness. While many mountain bike enthusiasts maintain that they should be able to enjoy their favored form of recreation on public lands, included those designated wilderness, land managers who oversee lands with wilderness characteristics are trying to prevent compromising those characteristics. And since officially designated wilderness is off-limits to mechanized travel -- even if that mode of transportation is a bike -- the forest managers are perhaps erring on the side of caution by moving to limit where mountain bikers can ride.

"There's no comparison between bikes made 20 years ago and those made today," Dave Bull, the Forest Service's director for recreation, minerals, lands, heritage and wilderness in Montana told the Times. "People are better able to get to places they couldn't reach before without hiking. They're pushing further and further."

Not only are the latest generation of bikes capable of taking their riders farther and farther into the backcountry, but their arrival, some believe, is out of sync with the wilderness concept.

“There is a wilderness experience, a truly backcountry experience, that is part of the idea and the concept behind wilderness," says Michael Carroll, associate director of The Wilderness Society's Wilderness Support Center. "It's preserving a landscape that is similar to the landscape that our fathers and their fathers before them were able to experience. It’s hard to argue that that experience has been preserved when you have heavy traffic zipping by on mountain bikes after you’ve spent two days hiking in.”

IMBA's communications director, Mark Eller, believes that sentiment can flow in two directions.

"Let’s reverse the hypothetical and say you’re in a remote area and you’re a solo mountain biker and you come across a gaggle of hikers," he offers. "Is that going to disrupt your quiet, the solitude on your mountain bike? Probably.”

Beyond that, says Mr. Eller, the debate over appropriateness, and righteousness, of trail use seems to be getting skewed.

“There seems to be the perception of conflict and the realities that people see on the trails are totally out of whack with each other," he said, adding a moment later that, "I have a hard time just categorizing one trail mode as always more pristine and contemplative than other.”

IMBA has worked to build alliances with the land-management agencies, from meeting around the country with officials to sending trail crews out to both repair trails and demonstrate how to build trails that will stand up to bike use. The group has not talked about cutting trails in national park wilderness areas -- though IMBA officials have talked in theory about realigning proposed wilderness boundaries to benefit mountain bikers -- but rather has focused on creating more riding opportunities elsewhere in the parks. With word that the New River Gorge National River is in line for $2 million to expand its network of bike trails, the group hopes to show that shared-use trails can be well-designed and used cooperatively by hikers and bikers.

“That’s what we’re hoping will be a great place for people to look to and see how it can work in a national park," said Mr. Eller, who agrees that not all national parks are suitable for backcountry mountain bike trails. "We think we’re going to be able to show how it can be done when it’s done right.”

While IMBA also has argued that the ban against "mechanized" travel in official wilderness should be reworded to one against "motorized" travel, that might create more of a battle than the group wants to enter in light of the longevity of that provision in the Wilderness Act, which was passed in 1964

“Any time you go back and modify the parent law, or parent legislation, you better do it with some good public debate, and I think that’s what needs to happen if we do need to go back and look at those things that were legislated in 1964," said the Park Service's Mr. Oye. "It’s not our intent to change the Wilderness Act to allow for mountain bikes, and it’s not our intent to compromise future wilderness designations by promoting mountain bike use in areas that” have potential to be designated wilderness.

At the Wilderness Society, Mr. Carroll adds that, “This is the camel’s nose under the tent. That’s been our argument for a long time. There’s no way you can say that they’re not mechanized. They say themselves that they want to see these big loop systems developed, and they say they want to be allowed in wilderenss. For us those things don’t add up.”

A mountain biker himself who enjoys riding the trails around Durango, Colorado, Mr. Carroll said the issue over mountain bikes in wilderness is personally a tough one -- "I've got tons of friends who are mountain bikers. It's a conundrum for me." -- but in the end he believes wilderness lands need the highest level of protection from impacts. With mountain bikes getting bigger and bigger, their impacts are getting larger, as well, said Mr. Carroll, referring to the Surley bike company's "Pugsley" model with its huge, 4-inch-wide tires.

“Protecting the resource, protecting it for what it represents, for the clean air and water, the wildlife, protecting it for future generations ... is the first priority of wilderness areas," he said. "We want to preserve that as a piece of the puzzle in terms of the management of our public lands. It’s not about 'our' use. ... I think it’s (the debate) unfortunate. There are so many people, if they could take a step back from their use and look at the larger resource issues, and the larger context, I wish they could see that this is about the greater good, not just about your specific use.”