The Bush administration altered critical portions of a scientific analysis of the environmental impact of cattle grazing on public lands before announcing relaxed grazing limits on those lands, according to scientists involved in the study.

A government biologist and a hydrologist, who both retired this year from the Bureau of Land Management, said their conclusions that the proposed rules might adversely affect water quality and wildlife, including endangered species, were excised and replaced with language justifying less-stringent regulations favored by cattle ranchers.

A BLM official acknowledged changes were made in the analysis but said they were part of a standard editing and review process and were based on "good science."

Critics often complain that the Bush administration has made a practice of distorting scientific studies to weaken regulations to serve its political objectives. Philip Cooney, a White House official who previously worked as an oil-industry lobbyist, resigned last week amid accusation that he repeatedly edited government climate reports in a way that downplayed links between greenhouse-gas emissions and global warming.

Grazing regulations, which affect 160 million acres of public land in 11 Western states, set the conditions under which ranchers may use that land, and guide government managers in determining how many cattle may graze, where, and for how long without harming resources.

The original draft of the environmental analysis warned that the new rules would have a "significant adverse impact" on wildlife, but that phrase was removed. The BLM now concludes that the grazing regulations are "beneficial to animals."

Eliminated from the final draft was another conclusion that read: "The Proposed Action will have a slow, long-term adverse impact on wildlife and biological diversity in general."

Also removed was language saying how the rules changes could affect endangered species adversely.

"This is a whitewash; they took all of our science and reversed it 180 degrees," said Erick Campbell, a former BLM state biologist in Nevada and a 30-year BLM employee who retired this year. Campbell wrote sections of the report pertaining to impacts on wildlife and threatened and endangered species. "They rewrote everything. It's a crime," he said.

Former BLM hydrologist Bill Brookes, who assessed the rules' impact on water resources, said in the original draft that the proposed rule change is "an abrogation of (BLM's) responsibility under the Clean Water Act."

"Everything I wrote was totally rewritten and watered down," Brookes said Thursday. "Everything in the report that was purported to be negative was watered down. Instead of saying, in the long term, this will create problems, it now says, in the long term, grazing is the best thing since sliced bread."

Campbell and Brookes were among more than a dozen BLM specialists who contributed to the environmental-impact statement (EIS). The others could not be reached or did not return calls seeking comment.

Ranchers hailed the rules.

"We're hopeful that some of the provisions will strengthen the public-lands grazing industry and give our members certainty in their business," said Jenni Beck of the National Cattlemen's Beef Association. "We are encouraged that this EIS demonstrates the benefits of grazing on public lands."

Vast acreage is needed to support a comparatively small number of livestock because topsoil is thin and grass generally is sparse in the arid West. Only 2 percent of U.S. beef is produced from cattle on public lands.

The new rules, published yesterday by the BLM, a division of the Department of Interior, ensure ranchers expanded access to public land and require federal land managers to conduct protracted studies before taking action to limit that access.

The rules reverse a long-standing agency policy that gave BLM experts the authority to determine quickly if livestock grazing is inflicting damage. The regulations also eliminate the agency's obligation to seek public input on some grazing decisions. Public comment will be allowed but not required.

Concerns about the condition of much Western grazing land have been heightened by persistent drought that has denuded pastures in some areas, causing BLM managers to close some pastures, and leading many ranchers to sell their herds.

The new rules mark a departure from grazing regulations adopted in 1995 under President Clinton and Interior Secretary Bruce Babbitt. Those regulations reflected the view of range scientists that a legacy of overgrazing in the West had degraded water resources, damaged native plant communities and imperiled wildlife.

"It's an explicit rollback," Thomas Lustig, staff attorney for the National Wildlife Federation in Boulder, Colo., said of the new rules. "What (Interior Secretary Gale Norton) did was take Babbitt's regs and found parts where they could put a hurdle in to undermine the reforms."

BLM officials said the new rules represented a step forward in improving the agency's management of livestock grazing.

Bud Cribley, the agency's manager for rangeland resources, said the report was written by specialists from different BLM offices. When it was finished, in November 2003, the agency believed it "needed a lot of work," Cribley said.

"We disagreed with the impact analysis that was originally put forward," he said. "There were definitely changes made in the area of impact analysis. We adjusted it.

"The draft that we published we felt adequately addressed the impacts. We felt the changes we did make were based on good science."

Background on Cooney was provided by Seattle Times archives.