In response to an increase in violations, the U.S. Forest Service is cracking down on snowmobilers who venture into prohibited areas in the Sierra Nevada.
The agency has increased the number of patrols to ensure that snowmobilers don't enter federal wilderness areas or other locations off limits to the machines.
"The largest percentage of folks who come out here don't want to go into the wilderness," said Jerry Meyers, an Eldorado National Forest law enforcement officer. "It's a small minority that gives you the problem."
South of Lake Tahoe, the Forest Service is stepping up enforcement in the Blue Lakes area of Alpine County.
Inside the Tahoe Basin, patrols are being increased in the Freel Peak-High Meadows area, the Meiss Lake region, Burton Creek State Park and wilderness areas open only to travel on foot or ski.
Wilderness areas were established by Congress in 1964 as a sanctuary from commercial activities and motor vehicles.
At Tahoe, snowmobiling is allowed at the Kaspian-Blackwood Canyon area, the groomed trails between Tahoe City and Mount Watson, the high country between Spooner Summit and Kingsbury Grade, and some of Tahoe Meadows above Incline Village, Nev.
Tahoe Meadows had been a major scene of conflict between snowmobilers and other winter sports enthusiasts until a compromise was reached in 2002.
Forest Service officials said the compromise is working by allowing limited snowmobiling while reserving most of the area for cross-country skiing and other nonmotorized sports.
Increased patrols and volunteer snowmobile guides also have eased tensions in the area, said District Ranger Gary Schiff of the Humboldt-Toiyabe National Forest.
The volunteers let other "snowmobilers know where the boundaries are and where they can go on a snowmobile," Schiff told the Tahoe Daily Tribune. "I inspected the perimeter and there was not a single track outside of where it was supposed to be."
Protected areas are clearly marked with signs. Violators can get a $100 to $500 ticket.