SALMON, Idaho (Reuters) - The Obama administration is seeking to lift Endangered Species Act protections from two of the most iconic symbols of the American West, the gray wolf and grizzly bear, in moves likely to spark fierce resistance from environmentalists.

Two grizzly bear cubs are seen in the Yellowstone National Park in this 1966 handout photograph. REUTERS/National Park Service

The administration intentions emerged in an interview on Wednesday with two top-ranking officials from the Interior Department, whose agency, the U.S. Fish and Wildlife Service, oversees federal safeguards for the bulk of imperiled species.

Both the grizzly and gray wolf occupy the figurative pinnacle of the greater Yellowstone ecosystem encompassing parts of Montana, Wyoming and Idaho. Previous efforts to remove them from the U.S. endangered species list have met with staunch opposition in court from wildlife conservation groups.

Environmentalists have raised concerns that while both species have made a comeback under protection as endangered species, their recovery could falter if they were de-listed, a move that would likely open the animals to public hunting.

Sportsmen and ranchers, who make up a powerful constituency in Western states, have strongly advocated delisting wolves and grizzlies, arguing the predators are diminishing herds of big-game animals like elk and are preying on livestock.

Both wolves and grizzlies were hunted, trapped and poisoned to near extinction in the lower 48 states before they were eventually added to the endangered species list.

Federal protection of wolves has been especially controversial since they were reintroduced to the wild in the Rockies in the mid-90s despite strong objections of ranchers.

Under pressure from livestock interests and state wildlife managers, the federal government in April 2009 removed the wolf from the endangered species list in Montana and Idaho while keeping protections in Wyoming.

But a federal judge in August 2010 ordered full listing restored, saying the wolves’ entire range in the Rockies must be treated as a whole, and that protections cannot be left intact in Wyoming while they were lifted in other states.

Dan Strickland, assistant interior secretary for fish, wildlife and parks, said on Wednesday that the Obama administration planned to propose lifting Endangered Species Act protection for wolves in all three states, and would seek congressional action if necessary.

Delisting means states would assume management of the estimated 1,700 wolves in the Northern Rockies -- about 1,000 more than the federal recovery goal for the species.

In the same interview, Fish and Wildlife Service Deputy Director Dan Ashe said his agency also “will delist the grizzly” in the Yellowstone region.

“We’re moving forward with the states,” he added, predicting final action within 18 months.

The estimated number of grizzlies in the Yellowstone area has risen to more than 600 from 136 in 1975, which exceeds the recovery goal of 500.

Yellowstone area grizzlies were delisted in 2007, and states promptly planned hunting seasons. But environmentalists gained a legal victory last year, forcing the government to re-list them, arguing that the federal government had failed to take into account such factors as climate change. They also questioned whether 500 animals was a viable population.

Environmentalists say getting Congress to bypass normal procedures for reviewing the health of protected species and judicial review of those efforts would undermine the Endangered Species Act, a cornerstone of American conservation law.

“Wildlife management decisions are supposed to be made based on science, not politics,” said Mike Leahy, Rocky Mountain regional director of a private group, Defenders of Wildlife. “It means every time a controversial critter comes up under the Endangered Species Act, Congress could whittle away protections needed to conserve the species.”