TUCSON, Ariz.— Conservation groups sued the Trump administration Tuesday for failing to protect the San Pedro Riparian National Conservation Area from livestock grazing’s damage.

The lawsuit, filed in U.S. District Court in Tucson, says the Bureau of Land Management’s 2019 plan for the conservation area sanctioned destructive levels of livestock grazing on protected lands, putting the area’s remarkable ecosystem at risk.

“We’ve spent nearly a decade pointing out the legal flaws with the BLM’s plans to keep cows in this fragile ecosystem,” said Cyndi Tuell, Arizona and New Mexico director for Western Watersheds Project. “We’ve given them the scientific evidence demonstrating livestock grazing is not compatible with the protection of riparian areas in the arid Southwest, yet they turned their backs on their obligation to this incredible place and we are left with no choice but to hold them accountable in court.”

The San Pedro River National Conservation Area was the nation’s first, created by Congress in 1988. It includes more than 46 miles of the San Pedro and Babocomari rivers and nearly 55,000 acres of riparian areas and uplands, including four of the rarest habitat types in the Southwest ― cottonwood/willow forests, marshlands, grasslands and mesquite bosques.

More than 400 birds, 50 species of reptiles and amphibians, and 80 species of mammals are found in the conservation area, making this area a world-renowned biodiversity hotspot.

“In creating and designating the San Pedro Riparian National Conservation Area, Congress explicitly required the BLM ‘conserve, protect, and enhance’ the natural resources found there,” said Sandy Bahr, director of the Sierra Club’s Grand Canyon chapter. “It is heartbreaking that the BLM took nearly a decade to develop a plan that utterly fails to do that, and that will, in fact, do harm to this ecological wonder.”

The BLM’s management plan authorized livestock grazing on four separate allotments and included a provision that allows the BLM to increase the number of livestock allowed in the future without seeking public input.

The decision also allows the agency to use “targeted grazing” by cows, sheep or goats anywhere in the conservation area under the guise of “vegetation management.” The livestock used for these experimental vegetation treatments would be controlled with electric fences and require new water sources, which could impact water levels in the San Pedro River. It is unclear how the BLM would notify the public about when and where the targeted livestock grazing would take place.

“BLM should not be surprised by this lawsuit,” said Todd Tucci, an attorney with Advocates for the West, which is representing the plaintiffs. “BLM has known for decades that Congress required BLM to manage this area to conserve, protect and enhance the conservation values of the San Pedro Riparian National Conservation Area. And a mountain of scientific information establishes that BLM cannot protect these values ― and the habitat for threatened and endangered species ― by allowing the continued and expanded livestock grazing in this area.”

The groups last week filed notice with the U.S. Fish and Wildlife Service and the BLM that the San Pedro conservation area’s management plan violates the Endangered Species Act because it fails to ensure that livestock grazing does not jeopardize threatened and endangered species or harm their critical habitat. Endangered species in the area include Huachuca water umbel, Southwestern willow flycatchers, ocelots, jaguars, desert pupfish, Gila topminnows, western yellow-billed cuckoos and northern Mexican garter snakes.

“Cows were supposed to be completely removed from the San Pedro, but they continue to devastate the Southwest’s last free-flowing desert river,” said Robin Silver, a cofounder of the Center for Biological Diversity. “The San Pedro is hanging on by a thread. It faces so many threats, from development to climate change to the border wall. It’s shameful that the people responsible for protecting this spectacular river are capitulating to the livestock industry.”

In a May 2018 letter to the BLM, 21 scientists urged the agency to exclude livestock grazing. If livestock grazing in the conservation area were reauthorized, they wrote, it would jeopardize the many aquatic and riparian species. The area’s critically important role as an ecological reference site would be lost, they wrote.

The area is the traditional territory of the Chiricahua Apache, Opata, O’odham, Hohokam and Sobaipuri people.