Wildlife advocates and environmental groups have announced that they are challenging the removal of federal protections for gray wolves across most of the U.S.

Two coalitions of groups filed formal notices over the past several days that they plan to sue the U.S. Interior Department in federal court unless protections are restored. The notices are required as a precursor to lawsuits brought under the Endangered Species Act.

The Trump administration last week finalized a decision that ends longstanding federal safeguards for gray wolves in the Lower 48 states except for a small population of Mexican gray wolves in the Southwest.

The move puts states and tribes in charge of overseeing the predators and could allow hunting to resume in Michigan, Minnesota and Wisconsin.

Gray wolves have recovered from near extinction in parts of the country with thousands now roaming the northern Rocky Mountains and western Great Lakes region and growing numbers of the animals in the Pacific Northwest.

But they remain absent from much of their historical range and wildlife advocates have said protections still are needed.

Colorado wildlife officials say they are planning to reintroduce wolves in the state in coming years under a voter-approved ballot initiative.