The Bush administration has distorted the costs and benefits of designating critical habitat for endangered species in Colorado and elsewhere to justify limiting land protection, a national environmental group has charged.

In at least three cases, analyses showing the economic benefits of designating critical habitat were deleted from final studies, a report released by the National Wildlife Federation said Thursday.

In others, consultants added the overall costs of the endangered-species program to costs of protecting habitat to justify reducing the size of protected areas, the group said.

"Even if you're a big believer in cost-benefit analysis, you would think they'd believe in doing it in an honest and forthright way," said John Kostyack, a wildlife federation senior attorney in Washington.

Last year, Bush officials eliminated more than 1 million acres from critical-habitat recommendations because they were too costly, according to the group's report, "Unsound Economics: The Bush Administration's New Strategy for Undermining the Endangered Species Act."

An Interior Department official acknowledged Bush officials had significantly cut critical-habitat plans, but he rejected the idea that the administration unfairly ignored benefits of those designations.

"Yes, there's been a lot of exclusions, but it's allowed under the law," Interior spokesman Hugh Vickery said.

Critical-habitat designations may be pared if the cost of protection exceeds the benefits - so long as the decision is not likely to lead to species extinction, he said.

"No one disputes that the loss of habitat is a major issue that faces endangered species and that conservation of habitat is the most important thing we can do," Vickery added. "The question is, what's the most cost-effective way to do it?"

"Critical habitat" is the area occupied by a species protected under the Endangered Species Act, plus additional land needed to conserve the population. The law requires that the U.S. Fish and Wildlife Service designate critical habitat when a species is listed - before, critics say, the species' needs are well understood.

Federal agencies are required to consult with the Fish and Wildlife Service about the effect of actions they authorize, fund or carry out on designated critical habitat.

Selective editing by the administration eliminated any reference to benefits from protecting the habitat of a Colorado bird, the endangered Mexican spotted owl, Kostyack said.

A 2002 cost-benefit report by the Fish and Wildlife Service concerning another endangered owl species referenced an economic work that showed protecting critical spotted-owl habitat would provide annual benefits of $50 to $120 per household in clean water and in healthy recreation economies, Kostyack said.

But no reference to economic benefits was mentioned in the wildlife service's final March 2004 critical-habitat report that focused on the Mexican spotted owl.

The Fish and Wildlife Service had originally proposed designating 13.4 million acres of critical owl habitat in Arizona, New Mexico, Utah and Colorado. But Bush officials slashed the proposal by 8.9 million acres in 2001.

Only 529,000 acres are in Colorado.

Last year, a federal judge called the administration's reduction of Mexican spotted-owl habitat "nonsensical" and ordered the agency to go back to the original plan.

Fish and Wildlife Service officials have argued that designating critical habitat for species already on the endangered-species list is time-consuming, costly and of little benefit to species.

But the government's own endangered-species reports showed species with critical habitat were twice as likely to be improving as species without it, according to the Center for Biological Diversity.

"They order their economists and biologists to eliminate any reference to economic benefits and then they say there are none," said the group's executive director, Kieran Suckling. "This shows the administration has completely cooked the books to support their ideology."

In March, the Fish and Wildlife Service issued an economic analysis of proposed critical habitat for threatened bull trout in the Columbia, Klamath and Snake river basins in the Pacific Northwest. Before issuing the analysis, which had been written for the agency by a private contractor, the agency deleted the entire 57-page section on the benefits of this habitat protection, which included income from sport fishing and better flows for agriculture.

Staff writer Theo Stein can be reached at 303-820-1657 or tstein@denverpost.com .