WASHINGTON (CN) — Environmentalists are gearing up for a court battle after the Trump administration booted gray wolves in the Lower 48 states from the endangered species list on Thursday.

“This delisting decision is what happens when bad science drives bad policy — and it’s illegal, so we will see them in court,” Earthjustice attorney Kristen Boyles said in a statement.

The administration praised the move as a conservation victory that hands the responsibility of protecting the gray wolves back to state and tribal wildlife management. Secretary of the Interior David L. Bernhardt said the delisting marks a successful recovery and is based on the best scientific and commercial data.

But Collette Adkins, carnivore conservation director at the Center for Biological Diversity, said the courts have time and again rejected the premature removal of wolf protections.

“But instead of pursuing further wolf recovery, the Fish and Wildlife Service has just adopted the broadest, most destructive delisting rule yet,” she said in a statement. “The courts recognize, even if the feds don’t, that the Endangered Species Act requires real wolf recovery, including in the southern Rockies and other places with ideal wolf habitat.”

The U.S. Fish and Wildlife Service has delisted the gray wolf while the species is “still functionally extinct in the vast majority of their former range across the continental U.S.,” Earthjustice warned in a statement.

The nonprofit environmental law firm warned that the government’s own experts found the delisting proposal lacked sufficient scientific evidence and was a premature move.

The administration says there are currently more than 6,000 gray wolves in the country, up from a population of around 5,500 during the Obama administration. Nonetheless, Boyles said the increased populations in the Northern Rocky Mountains and Western Great Lakes populations does not signal a “mission accomplished” moment for the wolf’s recovery.

Experts say there were once hundreds of thousands of wolves roaming the American landscape, before they were hunted to near extinction in the 20th century.

“Wolves are only starting to get a toehold in places like Northern California and the Pacific Northwest, and wolves need federal protection to explore habitat in the Southern Rockies and the Northeast,” Boyles said.

Under President Barack Obama, Fish and Wildlife had considered delisting the wolf, triggering over a million public comments in opposition to the proposal. Last year, 1.8 million Americans spoke out against Trump’s effort to delist, with another 86 House and Senate members and 100 scientists standing in opposition to the plan.

But Bernhardt said Thursday that the department has “recovered more imperiled species” under Trump’s watch than any other past administration.

The gray wolf joins 13 species that the Trump administration has determined are not threatened or endangered, while another seven have dropped from the endangered species list to the threatened list since 2017.

Republican lawmakers touted the delisting as a proper move that allows states to manage gray wolf populations while also protecting other native species and livestock.

Hunters and ranchers, a constituency with heavy pull in Western states, have long argued the wolves prey on livestock and big-game wildlife.

Montana Stockgrowers Association President Fred Wacker said in a statement that he applauds the administration and that “management is always more impactful and effective when managed by the state.”

Congressman Doug LaMalfa, a California Republican, called the delisting a “great win for the West.”

“Turning gray wolf population management back over to states and tribes will give back local control and inevitably save cattle, sheep, other livestock, and families from the threat of a [gray] wolf,” LaMalfa said in a statement.

Focused on the up and coming hunting season, Congressman Pete Stauber, a Minnesota Republican, also applauded the move as “empowering state agencies to responsibly manage the gray wolf will help to conserve our deer herd for generations while putting cattle farmers at ease.”

But renowned primatologist Jane Goodall warned that delisting the wolves and turning to state management means trapping and trophy hunting. She called on the public to speak out against the decision in a video released Thursday, saying wolves have the same or even more intelligence and emotions than domesticated dogs.

“They can’t speak for themselves,” Goodall said. “But how tragic if one could no longer hear the beautiful sound of their howling back and forth at night under the moon.”