Oregon Democrats Ron Wyden and Jeff Merkley said they introduced the amendment to the Federal Aviation Administration reauthorization bill to preserve the unique quiet and solitude of Oregon's only national park, without having to go through the time and expense of a full air management plan.

The National Park Service would get special authority to decide if a Bend helicopter company can fly tours over Crater Lake under legislation passed by the U.S. Senate on Monday.

Oregon Democrats Sen. Ron Wyden and Sen. Jeff Merkley said they introduced the amendment to the Federal Aviation Administration reauthorization bill to preserve the unique quiet and solitude of Oregon's only national park, without having to go through the time and expense of a full air management plan. The bill still must be reconciled with the House version.

"I see this as a first step in keeping our national parks free of noise pollution that can ruin visitors' experience of our national treasures," Wyden said in a statement. "Future generations should be able to travel there without noise disruptions and enjoy the same experience travelers from all over the world see today."

The helicopter company, Leading Edge Aviation, submitted an application to the FAA last year and has yet to hear from them or the park service, said its vice president, Travis Warthen.

"So far, all we've gotten is a run-around from both agencies," he said from Bend. "If the park now does a noise assessment and determines it's not a compatible use, then we'll go away."

Leading Edge Aviation wants to fly helicopters from an airport outside the park and stay at 1,500-feet following Rim Road part way around the lake. The company says at that altitude, the sound on the ground would be equivalent to a car driving by.

Crater Lake National Park Superintendent Craig Ackerman said park officials have not seen the company's application, but will be doing a study this year to measure how quiet the park is, in busy places along roads as well as in the remote backcountry. That way they will be able to say whether a given level of noise is intrusive. He noted that a recent artist in residence at the park studied sound as art.

"This will be as much art as science," Ackerman said of the study. "What is an acceptable sound for one person is not acceptable for another."

The National Parks Conservation Association would like to see the bill extended to the rest of the national park system, said Sean Smith, the group's northwest policy director.

"We are concerned that unless the language is adopted across the country, we will continue to see these problems," he said from Seattle.

Helicopters fly tours over several national parks, including Grand Canyon. But no new helicopter tours have been authorized since 2000, when a federal law regulating them was enacted. That law calls for FAA and the park service to cooperate in developing an air tour management plan.

Wyden's amendment would leave the FAA with authority over safety over Crater Lake, but give the park service a chance to deny the permit based on noise, without having to spend the time and money to develop a full-blown air management plan.

After an uproar over the tours in Oregon, Wyden brought up the issue in the confirmation hearing for park service Director Jon Jarvis, getting a commitment to protect the "fragile beauty" of the park.