Now, utility terrain vehicles (a kind of ATV on steroids) are allowing even more people to go even further into places once reserved for those with the perseverance to get there.
But while ATV and UTV ownership has skyrocketed in Idaho, with an estimated 100,000 already registered in the state, other recreational users have raised the warning flag that improperly ridden ATVs and UTVs are causing erosion and destroying existing trails as the machines continually get bigger.
The trend has prompted land management agencies to implement new regulations on where each type of machine can be ridden. It's also brought them together to create a new public awareness campaign.
The Idaho Department of Parks and Recreation, the Idaho Department of Fish and Game, the Idaho Department of Lands, the U.S. Bureau of Land Management and the U.S. Forest Service have recently joined forces to launch the Idaho Off-Highway Vehicle Public Information Project.
The Web site, idaho-ohv.org, is a repository of rules and regulations for the use of motorized vehicles on public lands, as well as links to OHV organizations across the state.
It's a timely effort as land managers struggle to deal with the estimated 10,000 new OHVs registered each year, at the same time federal regulations are tightening control.
Larry Tripp, district ranger on the Mountain Home Ranger District of the Boise National Forest, called the growth of OHV use "explosive."
"We've seen a huge increase in the amount of registered ATVs in the last five years," said Jennifer Wernex, communications manager for the Department of Parks and Recreation. "It brought to the forefront for land mangers the need to provide education for those folks."
In 2005, the federal government adopted the National Travel Rule, requiring that all public land management agencies create motorized travel plans designating specific areas and trails for various types of motorized use.
As part of those plans, off-route travel will be prohibited unless in specific areas, according to Tripp. Trail use designations are broken down at several levels: trails for single-track motorbikes; trails open to standard ATVs no wider than 50 inches; and trails open to all motorized vehicles including cars and UTVs, some of which have wheel bases as wide as a small Jeep.
So far, the BNF has created motor vehicle use maps for three of its five ranger districts—Cascade, Lowman and Mountain Home—and is working to finalize the remaining two by the 2009 deadline.
David Olson, BNF spokesperson, said that roadways and trails do not have to be signed to show allowed uses, making it more important to get a copy of the district map.
"It's incumbent on the operator to get a map," Olson said. "In the past, the requirement was on the agency to sign every trail."
It's no slap on the wrist for those who get caught in the wrong area. The offense carries up to a $5,000 fine or six months in jail. Of course, no one has actually been hit with the worst-case-scenario punishment. Officers have the ability to issue a citation with a lower fine, but it will still cost offenders several hundred dollars.
The BLM is in the process of creating similar plans for its districts, but unlike the USFS, the BLM is creating maps, posting signs and creating informational kiosks at trail hubs, said M.J. Byrne, public affairs officer on the BLM's Boise District. Travel plan maps are available online, at BLM offices and at the kiosks. Volunteers, many with OHV groups, are working on signing the trails.
OHV owners also face a change in licensing beginning in January, when all motorbikes, ATVs and UTVs will not only have to be registered, but display a special license plate.
House Bill 602 went into effect last July, but because of the complexities of creating the licensing program, it's only now gearing up. While registration will still be done through the Department of Parks and Recreation, licenses will be available through the Idaho Department of Transportation.
The growth in the popularity of OHVs is being attributed to several factors, including the terrain of Southwestern Idaho, where sparse vegetation and open ridgelines provide perfect conditions.
Wernex and others also credit the rise in ATV numbers to the aging baby boomer population, since the machines can help older recreationists access the backcountry with greater ease.
Byrne agreed that older recreationists are drawn to ATVs as a way to stay active in the outdoors.
"Earlier they may have ridden their bikes or they may have hiked, and now it's much easier to get on an off-highway vehicle," she said.
But increased use is also causing challenges for more than just land managers. Beyond dealing with conflicts between users, local law enforcement budgets are stretched thin whenever they have to rescue a lost or stuck ATV rider.
For Fish and Game officials, it's a matter of keeping hunters honest.
Growing numbers of both big-game and upland-bird hunters are taking advantage of OHVs to pack gear into camp, scout the terrain and even haul out a kill. But some less ethical hunters are riding cross-country, scaring up game and even hunting from their machines—something strictly prohibited.
"We've heard a lot of these stories," said Fish and Game spokesman Ed Mitchell about the testimony that shaped many of the department's OHV regulations.
"The impetus for all of this on our part came from hunters themselves," he said. "Hunters who don't use them, or used them limitedly, find their experience in the hunt is compromised by other people using [OHVs] there."
While Fish and Game does not have the authority to regulate where people can drive OHVs, it does stipulate that all federal and state laws must be followed. Further details are outlined in state hunting regulations.
Mitchell said there are concerns among wildlife managers that excessive OHV use is detrimental to game animals, which no longer have the sanctuary of isolated wilderness.
"It makes a huge difference," Mitchell said. "Not in the number of how many more [hunters] kill, but it has to do with running the critters around."
With limited staff available for enforcing the regulations, it often comes down to the hunters themselves to keep an eye on things.
"Most [hunters] who get in trouble for it are turned in by their fellow hunters," Mitchell said.
With limited staff, self-monitoring is the main way trail enforcement is done, and land management officials ask that all users show common respect for each other. They also ask that recreationists get a copy of the travel plans before heading out. Maps are available at BNF ranger stations, the visitors' center in Boise and online.
But when it comes down to basics, Olson has some simple advice: "Stay on the trails."