Work to delay an environmental impact statement on a plan to reintroduce wolves in Yellowstone National Park may lead to efforts to secretly transplant the animals in the park, a park official said.

John Varley, the park's research chief, said pressure exerted by congressmen in Western states to stall the statement may leave the park with a population of the animals and no way to control them.Varley and Norm Bishop, a park biologist, told members of the National Association of Interpretation that an impact statement would answer the concerns of ranchers, stockmen and outfitters around the park that wolves may leave the park and kill livestock.

Opposition from Wyoming's congressional delegation has been largely responsible for stalling the reintroduction of the wolf, often called the missing link in the Yellowstone ecosystem.

But Varley said the politicization of the issue began before the facts on its impact could be distributed.

"The positions by the politicians in (Wyoming, Montana and Idaho) have already been taken," he said. "However, the American public is overwhelmingly in favor of this initiative."

In Wyoming, about 1,400 people have signed petitions calling for reintroduction.

"If there is no action, the polarized views will become even more strident," Varley said. "Some of us fear that private groups or individuals will take it upon themselves to do this job for the agencies."

It would be relatively easy for a group to capture gray wolves in Canada and transplant them in remote areas of the park, Varley said.

He added once the wolves were discovered, they would be treated as an endangered species and subject to stringent protection measures.

Under the reintroduction plan, however, any wolf population would be considered experimental, giving officials flexibility in management to address concerns such as compensation for livestock and destroying animals that stray out of recovery areas.

Bishop countered arguments that the reintroduction of wolves would lead to broad closures of public land in the area of the park, saying only a small area of the park would have to be closed to accommodate the denning of wolves in the spring.