Twenty states and D.C. sue to undo federal rollbacks of endangered-species protections

A coalition of state attorneys general filed two lawsuits on Sept. 9 seeking to reverse recent federal changes that limit protections for endangered species. The cases, brought by 20 states and the District of Columbia, ask a federal court to reinstate regulatory standards that protect the habitats animals need to nest, mate and raise young.

The lawsuits are led by the attorneys general of Washington and California, along with Maryland and Massachusetts. They were joined by Arizona, Colorado, Connecticut, Delaware, Hawaii, Illinois, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia, Wisconsin and the District of Columbia. The suits were filed in the U.S. District Court for the Northern District of California.

The complaints say the agencies violated two federal statutes: the Administrative Procedure Act (APA) and the National Environmental Policy Act (NEPA). Plaintiffs contend the new rules ignore the purpose and history of the Endangered Species Act and prior court rulings, and that the rules abandon the law's precautionary approach by stripping longstanding regulatory protections. The suits target both the narrower definition of "harm" and the new critical-habitat designation process.

Interior said it will "vigorously defend its authority" to manage endangered species under the new guidelines. In the department's view, the lawsuit seeks to preserve what it calls a decades-old regulatory overreach that went beyond authority granted by Congress.

The cases are now in federal court. If the plaintiffs prevail, the regulations could be vacated or remanded, restoring the broader habitat protections. If the courts uphold the rules, agencies will continue operating under the narrower definitions and procedures, with potential consequences for habitat management, permitting, and conservation planning at federal, state, and local levels.

This litigation is an immediate legal challenge to substantive regulatory changes that narrow what the federal government can consider unlawful under the Endangered Species Act and that change how critical habitat is designated. The outcome will affect how agencies manage habitat protections for listed species and could reshape conservation enforcement nationwide.