TUCSON, Ariz.— Conservation groups have sued the Biden administration to force two federal agencies to comply with the Endangered Species Act and protect imperiled Mount Graham red squirrels in southeastern Arizona from extinction.

The lawsuit, filed Tuesday in U.S. District Court in Tucson, says the U.S. Forest Service and U.S. Fish and Wildlife Service have failed to acknowledge that the red squirrels are in extreme jeopardy, a designation that would require relocating recreational cabins and an abandoned camp from the animals’ best remaining habitat.

“It’s infuriating that federal officials refuse to acknowledge the facts and do everything possible to save these vulnerable little squirrels,” Robin Silver, a cofounder of the Center for Biological Diversity. “These structures should’ve been removed decades ago, but now the animals are clustered in tiny, isolated pockets of what little canopied forest remains. The squirrels are sliding toward extinction while the agencies worry about inconveniencing a few cabin renters who’ve known for 30 years that they needed to move.”

The Mount Graham red squirrels face a historically precarious habitat bottleneck. The cabins and abandoned camp occupy the only intact, significantly sized canopied, upper-elevation forested area on Mount Graham, which is ideal for the squirrels’ short-term recovery.

The 14 recreational cabins and a camp are in the Columbine/Ash Creek drainage near the top of the mountain. Earlier agreements with the agencies, in 1987 and 1988, required removing the cabins and camp to protect the squirrels.

“The squirrels’ survival is far more precarious than it was 30 years ago, with much less habitat and dwindling pockets of isolated populations,” said Charles Babbitt, Maricopa Audubon conservation chair. “It’s incomprehensible that federal officials aren’t doing more to save these little animals. They’re paid to protect endangered animals and they need to obey the law and legal precedent. That means creatures on the brink of extinction get the benefit of the doubt.”

The squirrels’ prime spruce-fir habitat and nearly all of their designated critical habitat are gone because of land acquisition by the University of Arizona administrators and astronomers, wildfires, fires set unnecessarily to protect the telescopes, and undue pressure exerted by former Sen. John McCain to keep the telescope project on track. The squirrels also have been harmed by the Fish and Wildlife Service’s weakened standards for plants and animals in jeopardy and the agency’s illegal failure to reinitiate consultation to save the squirrels.

Mount Graham red squirrels live solely in the isolated “sky island” range in the Coronado National Forest and feed on conifer seeds; only 109 remain on Earth.

“The recreational cabins and camp occupy the only canopied forest available for the squirrels to recover and, hopefully, thrive,” said Roger Featherstone of the Mount Graham Coalition. “To save the Mount Graham red squirrel these structures must be relocated as promised more than a generation ago.”

The White Mountain Apache tribe has urged the Forest Service to remove the structures to save the squirrels. In a 2020 letter to the Coronado National Forest supervisor, the Tribe’s cultural resources director said the Forest Service should consider “the sacred nature and spiritual power” of the squirrels, known as Na’iłtso Łisogé, or the “original keeper of fire.”

In response to an April 2019 lawsuit from the Center and Maricopa Audubon, the Fish and Wildlife Service agreed that designating additional critical habitat for the Mount Graham red squirrel may be warranted. The agency has yet to protect any of the habitat currently occupied by the red squirrels.