WASHINGTON -- The Bush administration Wednesday reiterated its opposition to giving free federal land to Clark County to build a heliport roughly 15 miles south of Las Vegas.

Transferring 229 acres of Bureau of Land Management property to the county would save the county an estimated $55 million dollars at the expense of taxpayers, said Scott Cameron, deputy assistant secretary for performance, accountability, and human resources at the Department of Interior.

"The department cannot support a conveyance of public lands that does not include a fair-market return to the taxpayer for the value of those lands," Cameron told senators reviewing the bill.

Cameron's comments came two weeks after the Senate approved giving the county the heliport land as part of an annual transportation spending bill. The House must agree to keep the heliport provision in the bill for it to become law.

Meanwhile, the Senate Energy Committee held a hearing on the measure in the event that the heliport provision is dropped, committee spokeswoman Marnie Funk said.

Sen. Larry Craig, R-Idaho, who chaired the hearing, questioned why the county did not seek the land for free through an application process available to public airports through the Federal Aviation Administration. A 1982 law enables cities or counties to petition the FAA to broker on their behalf for federal land.

Clark County Aviation Director Randy Walker said the FAA process would have taken too much time.

"The only expeditious way to get the land was to do it by legislation," said Walker, who added that environmental reviews on land purchases can take as long as three years.

The county is pursuing the BLM land as an alternative base for air tour helicopters that now fly out of McCarran International Airport. Las Vegas residents for years have complained about the daily drone from helicopters en route to the Hoover Dam and the Grand Canyon. And air tour operators are looking for a less expensive landlord.

Aside from the land's cost, Cameron said the Interior Department was concerned about proposed flight routes from the new heliport, routes that would send helicopters over the Sloan Canyon National Conservation Area.

"We have concerns about Sloan Canyon essentially being buzzed about 90 times a day," Cameron said in an interview after the hearing. "It would be nice if we could figure out a flight path around the desert bighorn sheep."

He suggested that senators reroute the proposed flight paths to steer clear of the canyon, a move that would draw opposition from either Henderson residents or the air tour industry.

A shift in flights to south of the canyon would add mileage to each journey, adding fuel costs to each trip. Directing flights to the north could send noisy helicopters over residential homes in Henderson.