Montana Republican Sen. Steve Daines last week formally introduced legislation in the Senate that would increase the fine for illegally landing a helicopter and other aircraft in designated wilderness to $20,000.

The move comes after a wealthy Bozeman couple was caught landing their helicopter in the Bob Marshall Wilderness to go on a fishing trip.

The pilot, Sam Schwerin, 48, of Bozeman was fined $500 — the current maximum under the law.

But the Daines bill received a lukewarm reception from conservation groups, who say it should be broader in scope.

In a letter to Daines, they ask for what they see as more effective legislation.

“Your legislation focuses solely on unauthorized landings of aircrafts in Congressionally designated wilderness,” the letter reads. “Such landings, while unfortunate and illegal, are not the only unlawful vehicles that impact wilderness and backcountry experiences. A much more common occurrence not addressed in your bill is illegal entry into wilderness and other closed areas by snowmobiles, dirt bikes, and other motorized vehicles, as well as illegal cross-country travel by motorized users.”

The letter is signed by representatives of Montana Wilderness Association, Montana Wildlife Federation, Back Country Horsemen of Montana, Bob Marshall Wilderness Foundation, Hellgate Hunters and Anglers, Friends of the Missouri Breaks Monument, Winter Wildlands Alliance, Montana Outdoor Hall of Fame, and Bob Marshall Wilderness Outfitters.

“We appreciate Sen. Daines taking a stand for wilderness areas,” Amy Robinson, conservation director at Montana Wilderness Association said in a release. “But if the goal of the bill is to ensure Montanans find the peace and quiet they need and expect when they go to public lands that are off-limits to motorized use, then his bill must address the more pressing problem of OHV and snowmobile use on all public lands where they aren’t allowed.”

“It’s extremely tempting for snowmobilers to cross the boundary into wilderness areas and other places where they aren’t allowed, and the riders usually get away with it because there isn’t nearly enough law enforcement patrolling these backcountry areas,” Hilary Eisen, policy director at WWA said. “A much stiffer fine, as Daines is proposing for pilots, would make people think twice and maybe three times about crossing that line.”

The letter also calls on Daines to support the Blackfoot Clearwater Stewardship Act, a bill that would enlarge the Bob Marshall, Scapegoat, and Missions Mountains Wilderness by nearly 80,000 acres. So far, Daines has not supported a hearing for the bill in the Senate Energy and Natural Resources Committee, which is a necessary step for it to receive a vote on the Senate floor, they claim.