The Department of Interior offered its final proposal on Thursday for sweeping changes to an Obama-era rule meant to conserve habitat for Greater sage-grouse, an imperiled bird that has come to symbolize the tension between energy development and conservation in the West.

In a 600-page environmental document, the Bureau of Land Management (BLM), an Interior Department agency that oversees more than 67 percent of the land within Nevada, reduced protected habitat for the bird, while creating more exceptions for following current regulations.

The debate over how to protect dwindling populations of Greater sage-grouse is one of the most complex and charged environmental issues across the roughly 165 million acres and 11 states where the bird roams.

In 2015, as the bird faced a listing on the Endangered Species Act, the states agreed to a detailed conservation plan aimed at improving sagebrush habitat for the bird. The plan, the result of a delicate compromise between Western governors, environmentalists and developers, was meant to avoid a listing, an action that would halt development and cripple rural economies.

Since taking office, the Trump Administration has looked to amend that plan. The documents released on Thursday were its latest action to make the 2015 conservation plan less rigid, and it was quickly slammed by environmentalists who said the amendments, instead of saving the sage-grouse, could make an Endangered Species Act listing warranted in the near future.

“We’re missing all the pieces that made the bird not warranted [in 2015],” Brian Rutledge, who directs the Audubon Society’s Sagebrush Ecosystem Initiative, said in an interview on Thursday.

In recent months, Gov. Brian Sandoval has supported some of the proposed changes and harshly criticized others. But Sandoval applauded the BLM for incorporating his administration’s concerns into the final environmental impact statement that was released on Thursday.

“We appreciate the opportunity to have worked closely with the Department of the Interior on our concerns, and thank them for incorporating our input into the final plan amendments,” he said in a statement that came out with the BLM’s press release announcing the final plans.

Earlier in the year, the Sandoval administration had pushed back on the BLM’s rollback of rules aimed at offsetting industrial damage on federal public land. Sandoval, a Republican, said those requirements, known as “compensatory mitigation,” were central to Nevada’s sage-grouse plan.

Under the 2015 plan, the Obama administration worked with each state to craft a state-specific plan to restore sage-grouse habitat. Nevada’s plan required developers on public land to offset their impacts by paying to restore sagebrush habitat elsewhere in the state. In that original plan, developers were required to improve enough habitat within the state that it created a “net conservation gain” — more sagebrush habitat would be improved than would be degraded. To achieve this goal, the state launched a free-market system to buy and sell credits for sagebrush habitat late last year.

But that system was placed in jeopardy this summer, when the BLM removed requirements for “compensatory mitigation,” and in most cases, made mitigation voluntary for companies that disturbed habitat on public land. 

Nevada officials placed sagebrush habitat restoration at the center of its plan because the flamboyant grouse, known for its elaborate mating ritual, is sensitive to changes in its habitat. The sagebrush sea that stretches across much of the West, and large swaths of the Great Basin in Nevada, provides food and predatory cover for the imperiled bird.

But in Nevada, where mining rather than oil is the primary extractive industry, development has never been the primary cause of sagebrush degradation in Nevada. Fire poses the largest threat to sagebrush in the Great Basin.

Even though mitigation is voluntary on federal land, it appeared on Thursday that the new plans would allow states like Nevada to impose their own mitigation requirements. If that provision remains in place, it would alleviate some of the concerns that the Sandoval administration had expressed.

“Within the proposed plan amendment, the BLM has determined that compensatory mitigation must be voluntary unless required by other applicable law and in recognition that state authorities may also require compensatory mitigation,” Matthew Magaletti, a sage-grouse coordinator with the agency, wrote in an email to The Nevada Independent.

If a state statute or regulation explicitly required mitigation for sage-grouse on federal land, then energy developers and other companies could still have to offset their impacts, even if federal land managers no longer require it.

Michael Saul, a senior attorney for the Center for Biological Diversity, said it was “far from clear” that the Thursday document would allow a state agency to require mitigation on public land. He also said the final plan created problematic loopholes to habitat protections for the grouse.

On Thursday, other environmental groups like the Wilderness Society criticized the plan.

“The tools we need to get [to net conservation] are no longer reliably in place,” Nada Culver, a senior counsel at the Wilderness Society, said of the plan.

The Department of Interior has argued that the plan have given the states more flexibility.

“With [Thursday’s] action we have leaned forward to address the various states’ issues, while appropriately ensuring that we will continue to be focused on meaningfully addressing the threats to the Greater sage-grouse and making efforts to improve its habitat,” David Bernhardt, the Deputy Secretary of the Interior, argued in the BLM press release.

In addition to adding more information about mitigation, the amended plan also removed designations known as Sagebrush Focal Areas, sensitive habitat that would have been protected from potential energy development.

Democratic Sen. Catherine Cortez Masto joined environmental groups on Thursday in faulting the plan for favoring commercial interests and not doing enough to incorporate local input.

“The Department of the Interior has decided to put the interests of the oil and gas industry ahead of the best interests of Nevadans,” Cortez Masto said. “This new plan undermines the delicate balance Western states had struck to ensure the protection of sage-grouse populations and strengthen economic development across the western United States.”