The proposed Ivanpah airport, which could eventually serve as many as 35 million passengers annually, is touted as critical to filling Southern Nevada hotel rooms in the latter half of the next decade after McCarran International Airport reaches capacity.

But the location of the airport within six miles of the Mojave National Preserve is prompting concern that jet noise, traffic and light from the operation would destroy the solitude of the desert refuge.

On Friday the Federal Aviation Administration distributed 380 comments from people on several sides of the issue. The feedback focused mainly on what's at stake for the preserve, Southern Nevada traffic and Las Vegas tourism if the Clark County Department of Aviation succeeds in building the new airport.

The FAA and Bureau of Land Management will use the feedback in the environmental review for the project, which could take as many as four years to complete. The earliest the proposed $7 billion airport could be in operation is 2017.

"A big busy airport next to a national park risks a fundamental incompatibility," said Dick Hingson, a Sierra Club member from Flagstaff, Ariz., who wrote comments critical of the proposal.

Hingson, who has led hikes in the preserve and done volunteer work on its behalf, said jet and automobile traffic could disrupt the serenity visitors seek when they make the trek to the 1.6 million acre desert park.

"In other words, it would be the total frustration of a trip for many people who come hundreds of miles for the purpose of experience the vast quietness of the Mojave National Preserve," he said.

Hingson was among people who urged project backers to at least consider another location.

Other comments said the future of tourism in Southern Nevada depends on the construction of a new airport in the Ivanpah Valley.

Rossi Ralenkotter, president and CEO of the Las Vegas Convention and Visitors Authority, wrote a one-page letter in support of the airport.

Ralenkotter said tourism, gambling and conventions employ 255,000 people in Clark County and the jobs are dependent on efficient air travel. According to Ralenkotter, each new hotel room generates 320 air passengers annually. There are nearly 38,000 rooms scheduled for construction by 2010.

"McCarran serves as the primary aviation gateway to the city and as it reaches capacity, it is critical that Clark County have a supplemental airport to serve this growth," Ralenkotter wrote.

Kara Kelley, president and CEO of the Las Vegas Chamber of Commerce, also supported the proposed airport.

Kelley urged the government to consider the effect on the Las Vegas economy without a new airport.

"(W)ithout sufficient commercial air service to support both tourism and business growth, the Las Vegas economy will be put at risk," Kelley wrote.

Other letter writers criticized the location of the proposed airport, more than 25 miles south of McCarran along Interstate 15 near Jean.

Jane Feldman of Las Vegas, a Sierra Club volunteer, said the airport would encourage too much development in an area that is home to a number of protected species, including an area where desert tortoises that are rescued from development threats elsewhere are relocated.

"It is the only place we use to take these endangered species out of harm's way," Feldman said. "It is across the street from that proposed airport."

Planes would be bad for the tortoises, she said, because they could distract the reptiles from seeking food and shelter.

"They watch the aircraft because they are used to having predators descend on them," Feldman said. Feldman also suggested the government study whether low-polluting trains to California could relieve pressure on McCarran and reduce the need for a new airport.

So far, the Clark County Department of Aviation has been determined to put the new airport at the Ivanpah location. Airport officials say they've studied several sites and Ivanpah is the best location.

That's because the Department of Defense reserves much of the airspace north of Las Vegas for military use. The airport also needs to be far enough south of Las Vegas to avoid conflict with traffic at McCarran and Nellis Air Force Base. The Ivanpah location is also close to existing pipelines for jet fuel, as well as the freeway and railroad tracks.

Deb DeMeo of the National Parks Conservation Association said she thinks it would be possible to build the airport without causing too much disruption in the Mojave National Preserve.

"What I have heard is Clark County wants to construct an airport that is environmentally friendly," said DeMeo, who added she hopes the comments prompt a thorough investigation into direct and indirect effect of an airport on the park.

One way to reduce the impact of the airport would be to raise the level of protection and management of open space surrounding the site, she said. That could make it less likely that development prompted by a new airport would reach too far into the preserve.

She also wants to keep open the possibility of putting an airport someplace else.

"Those other sites, I think they deserve a fair evaluation," she said. "Politically, whether they get them or not, I don't know."