The air tours have pitted tour operators against visitors frustrated with the noise for decades, but it has come to a head as new management plans are rolled out at nearly two dozen national parks and monuments.

One of the strictest yet was recently announced at Mount Rushmore and Badlands National Park, where tour flights will essentially be banned from getting within a half mile of the South Dakota sites starting in April.

“I don’t know what we’re going to be able to salvage,” complained Mark Schlaefli, a co-owner of Black Hills Aerial Adventures who is looking for alternative routes.

The regulations are the result of a federal appeals court finding three years ago that the National Park Service and the Federal Aviation Administration failed to enforce a 2000 law governing commercial air tours over the parks and some tribal lands. A schedule was crafted for setting rules, and many are wrapping up now.

But now an industry group is eying litigation, and an environmental coalition already has sued over one plan. The issue has grown so contentious that a congressional oversight hearing is planned for Tuesday.

Critics argue that the whirr of chopper blades is drowning out the sound of birds, bubbling lava and babbling brooks. That in turn disrupts the experiences of visitors and the tribes who call the land around the parks home.

“Is that fair?” asked Kristen Brengel of the National Parks Conservation Association, noting that visitors on the ground far outnumber those overhead. “I don’t think so.”

The air operators argue they provide unrivaled access, particularly to the elderly and disabled.

“Absolutely exhilarating, a thrilling experience” is how Bailey Wood, a spokesman for the Helicopter Association International, described them.

Sightseeing flights got their start in the 1930s as crews building the massive Hoover Dam asked the helicopter pilots working on the project to give their families flyovers, Wood said.

“It took off from there,” he said, jokingly adding, “Sorry, aviation pun.”

The issue hit a tipping point at the Grand Canyon in 1986 when two tour aircraft collided over the national park in Arizona, killing 25 people. Congress acted the next year and a plan was enacted to designate routes and minimum altitude for canyon flights.

Congress passed another round of legislation in 2000 with a goal of setting rules in other national parks. But bureaucratic difficulties and delays stalled compliance.

The Public Employees for Environmental Responsibility and the Hawaii Island Coalition Malama Pono sued, demanding something be done. Historically, some of the nation’s busiest spots for tour operators are Hawaii Volcanoes National Park, which is home to one of the world’s most active volcanoes, and Haleakala National Park.

In 2020, a federal court ordered compliance at 23 national parks, including popular sites such as Glacier in Montana, Arches in Utah and Great Smokey Mountains in Tennessee and North Carolina. That same year, the latest in which data is available, there were 15,624 air tours reported, which was down about 30% because of the pandemic, the park service said.

As of this month, plans or voluntary agreements have been adopted for most of the parks, although not all of them have taken effect. Work is still underway on five, the park service said.

Parks exempted from developing plans include those with few flights and those in Alaska, where small planes are often the only way to get around.

“Mostly, the plans have been pretty generous to the industry, allowing them to continue as they have done in the past with some limited air tours around these parks,” said Peter Jenkins, senior council for Public Employees for Environmental Responsibility.

His group went to court over a plan to allow a combined total of about 2,500 flights over the Golden Gate National Recreation Area and other nearby parks, alleging an inadequate environmental study.

Then came last month’s announcement about restrictions over Mount Rushmore and the Badlands.

“This isn’t a management plan,” complained Ray Jilek, owner of Eagle Aviation Inc. and its chief pilot. “This is a cease and desist plan, as far as I’m concerned.”

Andrew Busse of Black Hills Helicopter Inc. said his tours already don’t fly directly over Mount Rushmore. The park is relatively small, so the monument to the nation’s presidents is still visible from outside its boundaries, he said.

The plans are aimed at taking tribal desires into account. But Shawn Bordeaux, a Democratic state lawmaker in South Dakota and a member of the Rosebud Sioux tribe, said he hasn’t heard complaints.

“We don’t want them flying around trying to watch our sun dances or ceremonies or something,” he said. “But as for tourism, I don’t see why it’s an issue.”

A similarly strict plan has been proposed for Bandelier National Monument in New Mexico. Bruce Adams, owner of Southwest Safaris, flies a fixed-wing plane with tourists a couple times a week over the area known for the dwellings carved into the soft rock cliffs.

“Changing the route is going to force me to fly over Pueblo tribal lands that I have assiduously avoided doing for 49 years because I know it’s going to cause noise problems,” he said.

Glacier National Park, meanwhile, is phasing out the flights by the end of 2029.

Wood said the process has been “broken and rushed” and threatens to put some operators out of business.

“Litigation is one tool that is definitely under consideration,” he said.

But Brengel of the National Parks Conservation Association said the resistance doesn’t have much traction. An amendment to the FAA reauthorization bill that would have required the agency to factor in the economics of commercial air tours over national parks failed in July, she said.

“People go to Arches, people go to Hawaii to hear the sights and sounds of these places,” Brengel said. “It’s so utterly clear that the vast majority of people who are going to these parks aren’t going to hear the sounds of helicopters over their heads.”