Colorado joins lawsuits against federal Endangered Species Act changes
The lawsuits argue that the changes will imperil the species the act was meant to protect

Ryan Hagert/ U.S. Fish and Wildlife Service
Colorado has joined 21 other states in two lawsuits against the federal government’s changes to the Endangered Species Act.
The changes — published in July by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service — did two things. First, it rescinded the definition of “harm,” which protects against the disruption or destruction of habitat utilized by endangered and protected species, from the Endangered Species Act. Second, it created a new process for designating “critical habitat,” removing a regulation that automatically afforded those protections to listed species.
The federal government claimed that the goal of the changes was to return the act to its original intent, reverse government overreach and promote transparency, clarity, predictability and efficiency.
The lawsuits, however, allege that these changes run contrary to Congress’ original intent in creating the Endangered Species Act. The suits claim that rather than protect endangered and threatened wildlife and the ecosystems they depend on for survival, the federal government is making it easier for private companies and individuals to modify or degrade the habitats of listed species.
“Colorado is home to over 30 threatened and endangered species that are critical to stable and healthy ecosystems,” said Colorado Attorney General Phil Weiser in a news release. “The changes by the Trump administration put threatened and endangered species and their habitats at risk, undermining the comprehensive protections Congress mandated under the Endangered Species Act.”
Weiser filed the suit alongside attorneys general from Arizona, California, Connecticut, Delaware, Hawaii, Illinois, Massachusetts, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia, Washington, Wisconsin and the District of Columbia.
Rescinding the definition of harm
The Endangered Species Act was passed by Congress in 1973 in response to declining populations of plants and animals as human and economic development increased. It was designed to protect and recover species on the brink of extinction, including making it illegal to “take” — any action of attempt to harass, harm, pursue, hunt, shoot, wound, capture, kill, trap or collect — listed species.
Harm was not originally defined in the act, but two years later, the Fish and Wildlife Service adopted a definition that included habitat destruction and degradation. This was upheld by the Supreme Court in a 1995 decision.
In removing the definition in July, the Fish and Wildlife Service argued that this interpretation went too far by barring activities that did not directly harm an animal — which it claims is the original intent of the Endangered Species Act. Including habitat degradation or destruction in this was a case of government overregulation, according to the federal agency.
The new lawsuit filed in September argues that altering this definition “reduces protections for habitats and makes it easier for them to be damaged or destroyed, even when that destruction ultimately threatens the survival of protected species,” according to the news release from Weiser’s office.
The change has sparked a lot of concerns, including from the Colorado Department of Natural Resources — which wrote a letter opposing the changes in a May public comment — as well as from other wildlife officials and environmental groups. On Aug. 25, seven former heads of the U.S. Fish and Wildlife Service and National Oceanic and Atmospheric Administration Fisheries wrote a letter asking the Interior Secretary to rescind the rule.
The former leaders — who served under the Obama, Clinton, Biden and Bush administrations — wrote that while they have “differing opinions on many aspects of implementation” of the Endangered Species Act, that they all “agree that the recent reinterpretation of the term ‘harm’ will upend the law and lead to extinction for some of our most iconic wildlife.”
According to the letter, including habitat destruction as part of the definition of harm is “one of the most foundational protections in endangered species conservation.”
“Wildlife doesn’t disappear only when an animal is shot, trapped or poisoned. It disappears when the places it needs to feed, migrate or raise its young are destroyed,” they wrote. “Modification, fragmentation or outright destruction of habitat are the leading causes of species decline and extinction.”
Changes to ‘critical habitat’ and threatened species protections
The second lawsuit filed by Colorado and the other states pertains to two other rule changes, including revisions made by the Fish and Wildlife Service and the National Marine Fisheries Service to the designation process for critical habitat as well as the agencies’ repeal of protections for newly listed species.
Critical habitat is used under the Endangered Species Act to identify areas that are “essential to the listed species’ conservation,” according to the agencies’ Federal Register posting.
The agencies’ July change allowed for areas to be excluded if economic benefits or national security impacts outweighs the benefits of protecting it as critical habitat, “unless failure to designate the area will result in the extinction of a species.”
The second change repealed a rule that allowed species newly listed as “threatened” in the act to receive automatic protections. Under the change, the species will need individualized protection plans, which some wildlife advocates argue will lengthen the time it takes to protect species and potentially open up for more development-related exemptions.
In the Federal Register postings, the agencies wrote that the rule change is meant to comply with President Donald Trump’s executive order to “unleash” domestic energy production, which directed agencies to review agency actions that “impose an undue burden on the identification, development or use of domestic energy resources.”
“For too long, the Endangered Species Act has been weaponized to stop almost any new project in America, driving up costs for families, weakening our competitiveness and undermining our national security,” said Interior Secretary Doug Burgum in a July news release announcing the new rules. “At the same time, results have fallen short. Nearly 97% of species ever placed on the list remain there today. Success should be measured by species recovery and delisting, not by adding more species to the list.”
The lawsuit filed by Colorado and the other states argues not only do to changes defy the Administrative Procedure Act and National Environmental Policy Act, but also that the “rescission of automatic protections for newly listed threatened species is contrary to the law’s conservation purpose because it leaves threatened species without protection necessary for their survival, substantially increasing the risk that they will become endangered,” according to the news release.
The new process for designating critical habitats “will leave areas essential to species’ conservation without the protections that Congress intended,” the release adds.
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