The Department of Interior moved on Thursday to remove gray wolves from federal protection, pleasing congressional Republicans and rankling environmental organizations that plan to fight the decision in court.

“Glad to see it,” Montana Sen. Steve Daines who like many western Republicans supports less federal control over at-risk species, told CQ. “Any time we can move a species off the endangered species list should be a victory.”

In its announcement, the U.S. Fish and Wildlife Service said gray wolf populations had recovered significantly after nearly disappearing in the early 1900s and now moved freely in nine states.

“This constitutes one of the greatest comebacks for an animal in U.S. conservation history,” the agency said, adding that the proposal excludes the Mexican gray wolf.

“The gray wolf no longer meets the definition of a threatened or endangered species,” David Bernhardt, acting secretary of the Interior, said in a statement. “Today the wolf is thriving on its vast range and it is reasonable to conclude it will continue to do so in the future.”

The federal government first labeled gray wolf populations endangered in 1974, a year after the Endangered Species Act became law, and the designation has been fought in courts since. The Obama administration proposed delisting gray wolves in 2013 but federal courts struck it down, arguing FWS had not conducted adequate analysis of its impact on the wolf population.

Republicans who largely support reducing the federal role in managing the species are ecstatic about Interior’s proposal even though it could take years for the courts to resolve whether this removal will survive legal scrutiny. They believe western and mountain states have demonstrated they can oversee gray wolf populations and want far less federal oversight.

“I’ve been fighting to get them delisted for years now and I agree with the delisting,” Idaho Republican Sen. Michael D. Crapo told CQ. “Complete state management is what I think is the best outcome.”

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Hours after the Interior announcement, which is subject to public comment, environmental groups said they would challenge the decision in court.

“We’ll go to court to stop the Trump administration from prematurely stripping wolves of the lifesaving protections that rescued them from the brink of extinction,” Michael Robinson, a senior conservation advocate with the Center for Biological Diversity, said in a statement. “The livestock industry and trophy hunters want wolves dead, but we’ll make sure the feds fulfill their obligation to restore wolves across the country.”

The species population is about 5 percent of its historic levels, according to the center.

“It’s still a proposal,” said Bob Dreher, senior vice president for conservation programs for the Defenders of Wildlife. “If they finalize it, we would almost certainly sue.”