A coalition of environmentalist groups announced Wednesday that it is filing federal lawsuits to block development of the proposed Halls Crossing Airport at Lake Powell.

The groups contend that the airport is not needed and would cause irreversible environmental damage to the adjacent Glen Canyon National Recreation Area.Suits contesting Federal Aviation Administration support of the airport were filed Tuesday in U.S. appeals courts in Washington, D.C., and Denver. A third lawsuit - challenging a Bureau of Land Management land transfer to San Juan County for airport use - will be filed with the U.S. District Court in Salt Lake City within a week, said Terri Martin of the National Parks and Conservation Association.

Martin said her organization, the Southern Utah Wilderness Alliance, and the Utah Chapter of the Sierra Club are taking the legal action in response to an FAA determination that the airport will not cause significant damage to protected areas.

The controversial airport has been discussed, planned and debated since 1984, when local proponents first suggested that the existing gravel airstrip at Halls Crossing be paved and lengthened to 5,700 feet and support facilities be built to accommodate extensive commuter and recreation air traffic.

"This airport was originally proposed to serve a large private resort," Martin said. "The resort idea was clearly unrealistic and has been dropped, and the airport has no real purpose anymore."

Christine Osborne of the Sierra Club said park service personnel and visitors to the marinas at Bullfrog and Halls Crossing can be served by existing highways, the Lake Powell Ferry and a single, moderate-size airstrip at Bullfrog.

Spending $3 million or more for an airport at Halls Crossing would be a waste of taxpayer money, said Brant Calkin, executive director of the Southern Utah Wilderness Alliance. The funds could be better spent to develop basic transportation services in San Juan County and the Navajo reservation, he said.

State officials have endorsed the concept of a full-service airport at Halls Crossing as a means of encouraging tourists to spend more time and money on the Utah side of the lake rather than in Arizona.

Last year, Gov. Norm Bangerter and Republican members of Utah's congressional delegation met with Interior Secretary Manual Lujan at the Halls Crossing site to encourage federal participation in the airport development.

The governor said through a spokesperson Tuesday that his support of the project has not wavered.

The proposed airport would be located on scenic, rolling sandstone desert land next to Glen Canyon and about eight miles from Lake Powell, Martin said, adding, "That type of terrain would require blasting to build the runway."

Beyond the construction work, the groups object to the prospect of a large number of aircraft flying over scenic recreation and wilderness areas.

"Silence, solitude and the ability to get away from the grinding and growling of modern machinery is a major part of what draws people to Utah's national parks and wild lands," Martin said.

The groups accused the FAA of ignoring its own policy of requiring "all possible planning" to minimize harm and avoid adverse impacts. They cited FAA predictions that general aviation operations at Bullfrog and Halls Crossing will increase 100 percent by the year 2007 if the new airport is built.