On August 5, 2025, Sierra Club and allies won a federal district court lawsuit challenging the denied petition of relisting gray wolves as an endangered or threatened species under the Endangered Species Act (ESA) in the Northern Rocky Mountains (NRM).
Sierra Club and allies originally filed a petition to relist gray wolves as endangered or threatened in 2021, and the U.S. Fish and Wildlife Service (USFWS) denied them in 2024. The environmental coalition, represented by attorneys at the Center for Biological Diversity and Humane World for Animals’ Animal Protection Law department, subsequently filed lawsuits over the denial of the petition, and Senior District Judge Donald Molloy recently ruled in our favor.
Under the ESA, USFWS was required to consider whether gray wolves were endangered or threatened in a significant portion of their range. Sierra Club and allies argued the agency failed to do so because they (1) did not consider Colorado (where gray wolves have recently been reintroduced) (2) did not find West Coast wolves endangered or threatened, and (3) did not consider the wolves’ historical range in their analysis.
Judge Molloy agreed with Sierra Club and allies on all points, finding the agency unreasonably excluded Colorado from its analysis and thus its determination that West Coast wolves are not threatened or endangered was arbitrary and unlawful, and most impactful beyond the scope of this case, concluded that the definition of “range” under the ESA includes historical range. The “range” ruling is important in determining the ESA status for other endangered or threatened species, which, like the gray wolf, now reside in a constricted area of their prior range.
As a remedy, the court vacated (set aside) USFWS’ denial of the relisting petition, and remanded to the agency to reconsider whether to grant protections to wolves living in Idaho, Montana, and Wyoming, along with portions of Washington, Oregon and Utah.