Amanda Pampuro

(CN) — Environmental groups on Tuesday asked the 10th Circuit to revive a lawsuit seeking to limit lethal takes of female grizzly bears along northwestern Wyoming grazing allotments in the greater Yellowstone ecosystem.

The Center for Biological Diversity and the Sierra Club sued the U.S. Forest Service in March 2020 over grazing permits in Wyoming’s Bridger-Teton National Forest that they say relied on vague conservation measures and lacked adequate protections for female grizzly bears. Western Watershed Project filed a separate complaint which was combined on the docket.

The environmentalists argued grazing permits issued in the Upper Green River Area Rangeland Project violated the Endangered Species Act and the Administrative Procedure Act. A federal judge dismissed the case in September 2022 and the environmental groups appealed.

Before European settlement of North America, scientists estimate 50,000 grizzly bears roamed the continent. Today the bears are listed as threatened under the Endangered Species Act and number fewer than 800.

Although grizzlies have largely thrived under Yellowstone protections, deaths are on the rise. On average, 64 grizzly bears were killed annually from 2015 to 2018, more than double the death rates recorded in 2013 and 2014.

The Upper Green River Area in northwestern Wyoming has the highest lethal take rate for grizzly bears, with 37 deaths since 1999.

The federal government signed off on up to 72 lethal bear takes from the Upper Green River’s six grazing allotments over the course of the 10-year leases. The environmentalists contend that the grazing grounds have become a population sink requiring kill limits for females to ensure the bears continue to recover.

“A mortality sink is an area where mortality exceeds the rate needed for survival, and in the project area, there is a female grizzly bear sink,” argued Megan Backsen, an attorney with the Western Watershed Project.

Barack Obama-appointed U.S. Circuit Judge Scott Matheson asked whether grazing contributed to the decline of the grizzly bears.

“Whether or not grazing is the cause of the sink is irrelevant, but grazing now contributes to it,” Backsen replied.

Senior U.S. Circuit Judge Mary Beck Briscoe, a Bill Clinton appointee, directed U.S. Attorney Rebecca Jaffee to explain why the agency skipped on specific female take limits.

“If the overall population drops below 600, then there are no acceptable takes,” Jaffee said. “That demographic parameter ensures there will be no excessive removal of females.”

Jaffee also noted that grizzly bear takes go through a review process and that even without sex-specific take limits, sex could still be a consideration.

“I think it’s important to recognize the background here, that the grizzly bear’s recovery is a major success story, and that happened with grazing on these lands,” Jaffee argued.

Ranching groups have grazed along the Upper Green River for more than a century. As written, the permits allow roughly 8,000 livestock, 8,000 cows and calves, and nearly 50 horses to occupy the land.

Joseph Bingham, an attorney with the Mountain States Legal Foundation represented several intervening ranching groups. Bingham asked the court to keep the permits in place if it decide to remand the case back to the district.

“Vacating the permits would cause irreparable damage to the ranchers’ business," Bingham said.

Obama-appointed U.S. Circuit Judge Nancy Morris rounded out the panel.

The hearing was held at the Byron White U.S. Courthouse in downtown Denver and broadcast over YouTube. The panel did not indicate when or how it would decide the case.