RENO, Nev. - The former top U.S. land manager for the biggest gold mining state in the nation says a proposal in Congress to privatize public mining lands "would be catastrophic, both environmentally and economically."

Bob Abbey, considered an ally of the mining industry before his retirement in June as the Bureau of Land Management's state director for Nevada, said the proposal by Republican Reps. Richard Pombo of California and Jim Gibbons of Nevada offers false hopes to rural communities to attract new businesses.

"There is nothing positive about this bill unless you happen to have ownership in a mining company," Abbey said.

"Having spent half my life managing the public's land and being a proponent of responsible mining, I assure you this legislation is bad for American taxpayers," he said in a letter first published Thursday in the Reno Gazette-Journal.

Gibbons, chairman of the House Resources subcommittee on energy and mineral resources, disputed Abbey's assertions Friday. He said the proposed changes in the 1872 Mining Law that are included in a budget bill headed for a House-Senate conference committee are needed to allow companies to purchase - or "patent" - the federal land that housed their mining operations.

"The provisions currently before Congress will allow for the economic viability that mining operations have created in rural communities to continue after a mineral resource has been depleted," Gibbons said in a statement.

"Contrary to what Mr. Abbey would have you believe, current provisions of law are not sufficient to make sustainable development projects economically feasible," he said.

Nevada leads the U.S. and ranks third in the world in gold production, behind South Africa and Australia.

Abbey was a 25-year veteran of the agency including the last eight years as BLM's top official in Nevada, where the agency manages 48 million acres - an area about the size of Nebraska.

"The Pombo-Gibbons legislation will allow mining companies and other creative entrepreneurs to acquire public lands for less than market value wherever these interests have claims and can defend a mineral discovery," Abbey said.

"Mandating the wholesale transfer of public lands might play well with some constituencies but it is poor public policy," he said.

Leaders of conservation groups who have opposed permits for gold mining operations in Nevada have had little success with administrative appeals before the BLM and traditionally viewed Abbey as a friend of the industry.

"It just shows you that most of us - even folks who have staked out different positions over the years on how to manage public lands - are now converging in opposition to this bill," said Elyssa Rosen, a senior policy adviser for the Great Basin Mine Watch based in Reno.

Abbey joins a list of ex-federal land managers opposed to the measure, including former Forest Service Chiefs Mike Dombeck, Jack Ward Thomas and Max Peterson.

His letter came in response to one by state Assemblyman John Marvel, R-Battle Mountain, who said the bill would provide much needed relief to rural mining communities seeking ways to diversify their economy and increase the taxable private property land base.

Combined with the U.S. military and the Forest Service, the federal government controls about 85 percent of Nevada so "there is limited opportunity for entrepreneurship in rural areas," Gibbons said.

Critics of the bill "apparently do not understand the plight of rural Western communities surrounded by miles and miles of public land," Marvel said.

Their "assertion that this will precipitate a land grab is nonsense," he said. "Developers today aren't willing to make the substantial investment necessary to bring infrastructure to the rural West."

Abbey said many selected parcels would be adjacent to fast-growing communities or national parks, forests and wilderness "where lands would have the greatest resale value."

"Such entrepreneurs could acquire public land for around $1,000 per acre, block public access and then sell these lands to the highest bidder. In some cases, it would be the taxpayers buying back these very same lands to prevent actions deemed incompatible with the public good."