A group of Park Service retirees is warning Congress of a possible end run around a process for establishing the number of snowmobiles allowed in Yellowstone National Park.

The Coalition of National Park Services Retirees says it expects Montana Sen. Conrad Burns and California Rep. Richard Pombo to introduce measures that would allow 720 snowmobiles a day in the national park, resulting in greater air pollution and noise that would exceed standards.

Yellowstone currently allows 720 snowmobiles a day but has averaged about 250 daily in the past three winters and is in the middle of determining permanent regulations for the machines.

The coalition says it wants the issues to play out in the public process rather than in the legislative process, and it sent a letter to members of Congress Dec. 4 saying legislation would “force a radical departure from the National Park Service's overarching duty to conserve the national parks.”

The group fears the legislation would come in the form of riders added to a Department of the Interior and National Park Service funding measure, known as a continuing resolution, that would allow the department and agency to continue operating while a budget is being hammered out. The department has been operating under a continuing resolution since the beginning of the fiscal year, Oct. 1, but that resolution is set to expire. It must be renewed or the department would shut down, as it did in 2005 when national parks were closed.

Coalition Chairman Bill Wade says 720 snowmobiles would emit levels of air and noise pollution and disturbance of wildlife that could be avoided with snowcoach use.

“The riders' greater impacts to Yellowstone contradict what the American public has said by overwhelming margins that it wants,” the letter states.

Wade also said approving the legislation would establish a precedent that Congress' commitment to maintaining the cleanest air possible in certain areas of the country is expendable. Further, approving such riders would exacerbate snowmobile noise already violating Yellowstone's standards, he said.

“National Park Service studies demonstrated that snowmobile noise has exceeded Yellowstone's standards in the last three winters even as the number of snowmobiles entering the park has declined and converted entirely to the four-stroke machines highly touted by the snowmobile industry as cleaner and quieter,” the letter states.

The impacts from 250 snowmobiles in the park each day fall into the category of “major adverse effects,” interfering with visitor enjoyment and affecting those areas most accessible by the vast majority of park visitors, the letter states.

With 720 snowmobiles per day, “snowmobile noise would exceed Yellowstone’s standards by even greater margins,” it states.

The Park Service has also proposed capping snowmobiles in Yellowstone at 720 a day. Many environmental groups favor alternatives that allow fewer or no snowmobiles.

A draft environmental impact statement on the issue is undergoing a technical review by state and county officials in Montana, Idaho and Wyoming, as well as federal agencies. The Park Service will incorporate comments from those agencies before opening the document up for public comment in March. A final decision is expected in time for the 2007-08 winter.

The coalition's letter says that since 1998, the public has, in record numbers and by margins of more than four to one, urged phasing out the use of snowmobiles in the park and increasing snowcoach use.

“We ask for your leadership in ensuring that Yellowstone's highly positive transition is not reversed by the Burns or Pombo amendments, which defy National Park Service’s legal responsibilities, conclusive scientific findings, and the unprecedented tide of public insistence that standards not be lowered in our first national park,” the letter reads. “For all these reasons, we ask you to ensure that no riders are attached to any budget bills.”