Stevan Christiansen, district ranger at the Hiawatha National Forest, points to a sign prohibiting motor vehicle use near Castle Rock Ponds. He said the Forest Service is having trouble with offroad vehicles going off designated roads. The trail in the background has been used by ATV riders illegally. More than 100 members of the Sportsmen's Off Road Vehicle Association in St. Ignace and hundreds more tourists regularly enjoy the 1,000 miles of roads designated for all terrain vehicle (ATV) use in the eastern Hiawatha National Forest, but as the number of ATVenthusiasts increases, so does the number of riders going off-road, damaging forest land and animal habitats, points out District Ranger Stevan Christiansen.

The U.S. Forest Service wants to reduce the number of riders going off-road by providing maps showing where ATVs and other vehicles are allowed.

"We're getting people riding ATVs where they shouldn't be," Mr. Christiansen said. "We want ATV-ers to come and enjoy the forest. We also want them to be compliant with the map, and the map is very clear that off-road use is not permitted in certain areas. We don't want off-road vehicles anywhere on the forest itself."

U.S. Forest Service Law Enforcement Officer Joe Orsini said the forest service uses signs and road blocks, including gates, large rocks, and fallen trees, to prevent ATV riders from venturing down certain trails and roads. More than 100 warnings and violations were issued to ATV riders last year, a number that has increased steadily over the past several years, he said. He would not release the exact figures.

No trails in the Hiawatha Forest in the Eastern Upper Peninsula are designated specifically for ATV use; riders share roads that are open to all vehicles. Other roads in the forest are designated specifically for highway-legal vehicles only.

"If you can't fit a vehicle on it; it's illegal, because there's only road riding on this side of the Hiawatha," he said. "For any offroad vehicle, it's all roads; there's no specific trails. So if you're on a road; you're probably good, but look at the map, that will really tell you. It's the ones that are on the user-created trails that are causing most of the damage."

Violators can be charged with a variety of violations for the illegal act, including going off-road, damaging certain types of plants, and going around roadblocks. Because the forest is federal land, the violations are federal offenses punishable by up to six months in federal prison and a $5,000 fine.

Steve DuFresne of St. Ignace, president of the sportsmen's offroad group, said his group is working with the Forest Service to create trails designated specifically for ATV use as well as working to keep its members from going where they are not supposed to go. Members are also working to get a "scramble area" set up where riders would be allowed to tear up the ground without consequence.

He also sees the development of trails as a way to draw more recreational enthusiasts to the area.

"It's a long, slow process, especially when you only have a few people working on it. Eventually, we'd like to get a trail system because people would come up here and spend their money if they had a place to ride other than the roads," Mr. DuFresne said.

The two halves of the Hiawatha Forest are limited by the U.S. Department of Agriculture to about 2,100 miles of road usable by all vehicles, with roughly 1,000 miles in each half. That limit is already met, so if the Forest Service wants to designate a road usable by all vehicles, including ATVs, it has to take that designation away from an equal stretch of road elsewhere within the forest.

Funds appropriated to the Forest Service that could be used to create ATV-specific trails are often used to repair damage made by riders who venture into prohibited areas, Mr. Christiansen said.

"We can apply for grants to repair damage on the national forest, and we can apply for more law enforcement. But the key is, if we can get people to not do that kind of stuff, then that money can be put toward trail development," he said. "I think our challenge here is to get people to understand why we don't want them riding through the swamps."

A user-made trail or rut can take between 10 and 100 years to be rehabilitated by nature. Depending on how much damage is done to the forest by ATVs, rehabilitation to a site can cost several thousands of dollars, Mr. Christiansen.

Road maps of the forest are updated each year and riders should obtain an updated copy when they are released each spring, Mr. Christiansen said. The maps are available at the Forest Service information and welcome center on US-2 near St. Ignace, area chambers of commerce offices, and many local hotels and gas stations.

"What we want is voluntary compliance. We want the public to police themselves, too," Mr. Orsini said. "I think that's a hard thing for people to understand, that it does cause damage when they're off road."