Some congressional members have long wanted a rider on the defense spending bill to limit the U.S. Fish and Wildlife Service's ability to list as endangered the greater sage grouse, a flamboyant bird that roams much of Nevada. Since listing the bird would place more restrictions on land use, the debate over whether to list the bird has come to symbolize a larger dispute between conservationists and industry over managing federal lands.

In years past, Sen. John McCain, as chair of the Armed Services Committee, had blocked the riders from advancing past the House of Representatives, pointing out that they had little to do with the military. But in McCain’s absence this year, some believe the riders could succeed, reported E&E News, a trade publication that covers the politics of natural resource issues.

And the issue is spilling into the Nevada Senate race.

On Monday, a campaign spokesman for Sen. Dean Heller, a Republican, issued a statement that criticized his Democratic opponent, Rep. Jacky Rosen, for opposing the rider. It accused her of “caving to the desires of California environmentalists like Nancy Pelosi and Tom Steyer.”

“Her careless vote shows she’s more concerned with pleasing her tree-hugging donors who want to take away Nevadans’ access to their public lands rather than helping hardworking rural Nevadans make ends meet,” a campaign spokesman, Keith Schipper, said in a press release.

The rider prohibits the Fish and Wildlife Service from listing the sage grouse as an endangered species for at least 10 years. For years, politicians across the Intermountain West have argued a listing would severely restrain industry in rural areas that overlap with sage grouse habitat.

During the Obama administration, a bipartisan group of Western governors, including Gov. Brian Sandoval, worked with the Fish and Wildlife Service to avoid a listing. The deal struck was that the Fish and Wildlife Service would defer a listing until at least 2020 if the states developed detailed conservation plans. Yet the plans and subsequent actions by the Trump administration to make them less ironclad have triggered numerous lawsuits from both state officials and conservationists, adding uncertainty to whether the sage grouse will be listed in the future.

Through the rider, Congress would ensure that the bird could not be listed for the next decade. According to a letter E&E News posted, Democrats on the House Armed services Committee have argued that a listing decision should be made through a science-based approach, not by Congress.

Despite Rosen's vote against the rider to prohibit a sage grouse listing for 10 years, it passed and was included in the defense spending bill, which she later voted for in committee. Stewart Boss, a spokesman for Rosen’s campaign, said that she supported the 2015 sage grouse plans.

“These ongoing conservation efforts to protect the sage grouse's habitat have already successfully kept them off the endangered species list,” Boss said in a statement. “Congresswoman Rosen supports this flexible approach for sage grouse conservation in Nevada, and she believes interference at the federal level into a process that is working - whether it's the Republican Congress or the Trump Administration - is unhelpful and unnecessary.”

The defense bill could also include language giving the Pentagon more permanent control over land at the Fallon Naval Air Station and the Nellis Test and Training Range. Both test ranges have plans to expand and are in the process of conducting environmental analyses. Under the current rules, land expansions must be revisited after a certain period of time, around 20 years.

If passed, a provision in the bill would make the expansions indefinite. Jose Witt, the Southern Nevada director for Friends of Nevada Wilderness, said the group is watching the bill closely.

“It’s definitely something we’re concerned about,” Witt said.

Witt said, in the past, the organization would have relied on McCain or Sen. Harry Reid to kill such a provision. But he said he’s confident that indefinite land withdrawals do not have strong Senate support. He said that he expects hunters, in addition to conservationists, to oppose it.