FIRST OF THREE PARTS

State Conservation Officer Matt Miller stopped his truck at the edge of the Rum River, just in time to see the wet joyrider.

A young man on an all-terrain vehicle was driving down the center of the shallow river, waves of mud and water pouring away from his machine. It was the kind of destructive fun that draws many ATV riders to Minnesota's public lands and waters. It's also against the law.

The thrill-seeking rider drove up on the bank. Miller followed in his truck, to the man's nearby home and wrote him tickets. Returning to the Rum River, a state wild and scenic waterway north of the Twin Cities, Miller photographed a stretch of once-green shoreline that had been scraped into black ruts by ATV wheels.

"It seems like some of them think they can ride anywhere they wish regardless of what guidelines and laws there are," Miller said.

Across Minnesota, as ATV ridership soars, the wildly popular pastime is exacting a lasting, costly toll on the state's forests and wild lands.

Fragile wetlands are being churned into mud. Wildlife habitats are being torn up. Lake and river beds are being rutted. Hillsides are being eroded.

Five years ago, Minnesota enacted laws to keep all-terrain vehicles on trails. But officers like Miller keep catching riders doing the opposite.

To the dismay of lawful riders, renegades on four-wheelers are being caught damaging forests and trespassing on nature areas and private lands across the state, a Star Tribune analysis of five years of Department of Natural Resources enforcement records shows. Some are ignoring signs or driving around barriers put up to stop them. Others are brazenly posting videos of destructive riding on YouTube.

With stepped-up enforcement, nearly 1,600 riders have been issued tickets or written warnings for off-trail lawbreaking, but that's only a fraction of the violators, most of whom are never caught.

"You see the damage, you see the aftereffect of what's been happening, so you assume there are a lot more out there than we're catching," said Colleen Adam, a DNR conservation officer assigned to ATV enforcement.

Regulating ATV riding on public land has become a dominant issue for the DNR, which at times is divided over how to respond to the go-almost-anywhere vehicles. As ATV registrations have nearly tripled in the past decade, to 264,000, there's also unrelenting conflict between four-wheeler fans and hikers, canoeists, bird watchers and others who prefer quiet in the woods.

The DNR hasn't documented the full extent of ATV damage on public lands or estimated the cost of repairing it. But recent DNR monitoring efforts found problems in 17 state forests.

A Star Tribune investigation of ATVs on state lands also reveals:

• Renegade riders caught trashing the environment usually face small fines, seldom pay restitution and never lose driving privileges. The DNR doesn't enforce a 2005 law to keep the worst violators off ATVs, saying it doesn't have the money to do so.

• Riders often use state-approved trails to illegally enter sensitive places. Nearly one in four tickets or warnings issued for riding in wetlands and public waters occurred near places where it's legal to go, the DNR's data show.

• ATVs now represent the third-biggest claim on conservation officers' patrol time. Officers spend more hours checking on ATVs than they do on waterfowl and small-game hunting or snowmobiling. Yet the DNR Enforcement Division is roughly the same size as a decade ago -- a little more than 200 officers and supervisors.

DNR Commissioner Mark Holsten said the department is trying to change the virtually unregulated riding culture of the past -- a difficult job that is far from finished.

"It is offensive to me to have people say that it is not better out there than it was pre-2003," said Holsten, referring to the year new laws took effect.

To get the problem under control, the DNR is now taking the controversial step of paying rider clubs to act as "Trail Ambassadors" who encourage riders to obey the law. The agency also is closing many trails, and mapping thousands of miles of ATV routes in a hotly debated five-year review of motor use in state forests.

Damage? Check YouTube

Anyone who wants to see what ATVs can do to the environment need not go into the woods. Riders' exploits are posted all the time on YouTube.com, the video-sharing service on the Internet.

That's what Conservation Officer Paul Kuske discovered last year. Acting on a tip, he searched YouTube, and spotted a clip from the Pine Center ATV Trail, a 23-mile network on county and state land in Whitefish Lake Memorial Forest near Brainerd, Minn.

Wetlands lie adjacent to that trail. Watching the YouTube video several times, Kuske said he was "90 percent certain" he recognized at least one site. The clip showed ATV riders repeatedly driving through muddy areas just off the trail, including protected wetland. Kuske couldn't identify the riders: They wore helmets; mud covered their license plates.

Kuske said he was too busy to seek a subpoena ordering YouTube to name the video maker. The investigation stalled, no one was arrested, and the video disappeared from YouTube.

To protect the areas, foresters placed keep-out signs at the sites. Kuske also warned many ATV riders that the trail could be closed if violations persisted. He said it has helped.

Still, this spring, someone ripped out two DNR signs at one site featured on YouTube. Fresh tracks led into the mud. So the Star Tribune placed a hidden, motion-activated video camera there in June. It recorded a man and a woman riding ATVs into the mud and getting stuck (see it on StarTribune.com).

Under state rules, it is illegal for ATV riders to cause erosion or make off-trail ruts. Kuske, after being shown the new video, said that if he caught the riders, he likely would issue a written warning, rather than a ticket, because the keep-out signs were gone and the area isn't a protected wetland.

Some officers are experimenting with hidden cameras to gather evidence of destructive off-road riding, and one even led to a prosecution in Kittson County. But the videos usually don't clearly show the license plate or riders' faces, enforcement officials say.

"Isn't hurting anything"

More often, it takes luck to catch ATV riders ripping up the landscape.

Last September, conservation officer Miller got a call from a radio dispatcher reporting that ATVs had been seen in the Rum River in Isanti County.

Miller drove to a boat landing. He was just in time to see Delorne Kluck, then 20, "riding down dead-center in the river."

The officer followed Kluck to his house near Cambridge, and confronted him. Kluck was polite, Miller said, but insisted that he did nothing wrong, though he later paid a $300 fine. Two friends also got tickets.

It was Kluck's second bust for damaging the environment on an ATV. In June 2006, he was caught by other officers patrolling the Red Top ATV Trail, just east of Mille Lacs Lake, after he drove into a wetland.

"I still don't think it was a wetland," said Kluck, who paid a $100 fine for that violation. "It was just a trail with mud on it."

Kluck said that "most riders want to do stuff that's a challenge and see if they can make it through it. " If his ATV gets dirty, he washes it off by riding in the river, he said.

"For the most part this stuff we ride in isn't hurting anything," he said. And the DNR "makes it sound worse than it is so that people won't do it anymore, " he added.

Officers write tickets or warnings to about 439 ATV riders each year for damaging the land or off-roading where they shouldn't, the DNR data show. That includes 52 riders, on average, caught in waters or wetlands. Another 386 people are stopped for driving illegally in parks and preserves, in roadside ditches during bird-nesting season, in hunting areas during restricted hours or on private lands.

The worst lawbreakers keep riding. At least 42 people have been charged with careless or reckless ATV violations since 2005, but they didn't lose riding privileges despite a state law. Nor did they have to take a class and pass a state test before riding again, as the law requires. DNR acting enforcement chief Mark Johanson said the agency did not get money from the Legislature to track the offenders and impose the extra sanctions.

Increasingly, officers are turning into woodland traffic cops. They issue, on average, 3,400 tickets and warnings each year for safety and vehicle registration violations. That work is crucial to reducing ATV accidents, injuries and deaths, but means less time protecting natural resources.

Powerful ATVs can alter the landscape in a variety of ways. If ATVs ride in grassy agricultural ditches during the April-to-August closed season, pheasants often won't nest there, said Carmelita Nelson, who coordinates a DNR Roadsides for Wildlife program. Seeds from invasive weeds can be carried on muddy ATVs, and damaged wetlands often grow back with Reed canary grass instead of native plants.

Rarely made to pay

Only in rare cases are destructive riders made to pay restitution for tearing up the land.

One is Trevor James John of Crosslake, a former snowmobile racer. He was caught four years ago with his ATV stuck in a wetland at Flanders Lake near Brainerd.

John said he and a friend were "just out enjoying nature." The DNR complaint said they drove unregistered ATVs past a sign that said, "No motorized vehicles allowed beyond this point," and then got stuck in a wetland. Conservation officer Karl Hadrits, who spotted the ATVs, slogged through thigh-deep mud to reach the two riders.

After long court delays, a judge last May ordered John to pay $400 restitution, on top of an earlier $377 in fines and fees. John said he paid the money to make the case go away.

His ATV wasn't confiscated. Although conservation officers seize firearms, fishing gear, boats or fish houses for various violations, the seizure law doesn't apply when people damage the land with a vehicle.

"Why would you buy like a 4-wheel-drive ATV if you can't even go in mud?" John said. "... It wasn't like we were the first ones riding there. There were tracks all over the place. People have ridden there for years ... I don't understand what it is we are ruining to drive an ATV there."

Hadrits has busted numerous wetland violators, including people driving giant-wheeled trucks. At trouble spots, he hides in the woods, binoculars in hand, his ATV parked and ready to roll.

"Sometimes to catch people you have to sit back and hide and watch -- and it takes time," he said. In one stakeout, he chased three riders on his ATV for nearly 4 miles after they rutted up a lakeshore and then sped away.

Riders sometimes help. While patrolling the Pine Center Trail in May 2007, conservation officers Kuske and Miller met two riders who said that two kids on ATVs were stuck in a bog down the trail. "Sure enough, they were right up to the handlebars," Kuske said. "... They had been in here for probably a good half-hour or better, ripping around and going around."

The boys had driven around a keep-out sign and barrier logs.

The clear-water bog, once the home of wood ducks, "was like a pudding. It was so churned up, completely devoid of vegetation, even around the edges, just one big soup hole," he added.

As Kuske and Miller questioned the 17-year-old boys, from Champlin and Dayton, the two riders who reported the incident returned -- angry at the kids' behavior.

"They wanted a piece of these guys," Kuske said, who intervened to prevent a violent confrontation.

Some ATV riders worry that destructive acts damage the image of their sport and will sour Minnesotans -- the vast majority of whom don't own ATVs -- on allowing motorized trails on public lands.

"If we have all these bad apples digging up the mud all over the place ... pretty soon no one is going to have a spot to ride," said Dan Scholl, president of the Eastern Morrison County 4-Wheeler Club. "And we are out for more trails. To get more trails, we have to keep everybody from making it look like a bad sport."

Fixing the scars

Environmental damage from ATVs, however, is more than bad PR. Scarred landscapes can be costly to fix and take years to heal.

Nowhere is this more visible than at Spider Lake Recreation Area in north-central Minnesota, where 26 miles of trails became a magnet for ATVs and 4-wheel-drive trucks early in the decade.

It once featured a hillside deliberately strewn with boulders and logs for trucks to scramble over. The eroded "challenge hill" has been closed, and the DNR has spent $450,000 since 2003 to deal with wetlands, lakeshores and hillsides damaged by illegal ATV riding.

Some areas at Spider Lake are recovering, yet new ATV damage is visible. Last Memorial Day weekend, conservation officers ticketed or warned 10 ATV riders for driving off the trail, including two who rode around in a wetland.

"You get, lots of times, younger groups maybe in their 20s or early 30s who think that they're on their own little private piece of property and they're going to do what they want to do," said DNR conservation officer Chad Sherack, who patrols the area.

Even minor damage, such as ATV ruts, can become a costly problem. At Sugar Hills, a cross-country ski area near Grand Rapids, Minn., almost every hillside has been damaged by illegal riding over the past 10 years, said Bruce Slinkman, president of the Minnesota Nordic Ski Association and a contractor who sometimes has been hired to smooth and regrade trails.

On hills, the ruts gradually erode into gullies after a few rainfalls. "I have encountered gullies that are 2 feet deep to a couple cases that are 4 feet deep -- the trail is impassible," he added. It costs $1,000 just to bring heavy equipment into the woods for a day, and a repair job can easily cost double that, he said.

Since 2006, when DNR established the first of two damage-monitoring programs, field workers have reported wetland damage or signs of illegal off-trail riding in 17 state forests and other scattered state land.

Yet many of the state's 58 forests have not been checked for such damage.

"I don't claim that we're doing anywhere near 100 percent monitoring," said Keith Simar, recreation coordinator for the DNR Forestry Division. "Our direction to foresters is to deal with the issues as we come across them in our normal work, not to go out and try to find unfound problem sites."

Simar said he sought $100,000 to systematically look for forest ATV damage, but the money wasn't approved.

State and county foresters have placed signs, downed logs, fences and boulders to keep out ATVs. Those efforts haven't always worked. At one spot near the Mississippi River headwaters, determined riders have repeatedly moved large rocks blocking a favored unauthorized riding area.

A few good boulders

In Beltrami County, foresters recently discovered a way to keep vehicles out of closed areas: 5,000-pound boulders.

Rocks smaller than about 3 feet in diameter can be yanked aside by a 4-wheel-drive truck, said John Winter, who heads county recreation programs. The county paid a contractor $14,000 to place about 35 boulders, other barriers and signs at eight closed access points to the Mississippi Headwaters State Forest.

Logs and branches also have been put on closed trails, and in another innovation, workers scatter soil over the piles. If anyone tries to cut the logs, grit will ruin the chainsaw.

At one spot where old keep-out signs and barriers had been ripped out, workers embedded new signposts in concrete. "We fortified that one and, by God, it worked," Winter said.

He believes it will take years, and pressure from riders who don't break the law, to change the thinking of those who do.

"I am hoping they will help to influence the ones who are raising hell," Winter said. "To say we are going to get all the resource damage under control, that is going to take a hell of a long time."

Star Tribune photographer Brian Peterson contributed to this article.