When did all this get started?
The law was enacted in 1906 to prevent looting of Indian artifacts from archaeological sites. The act has mostly been used since then by presidents to turn public land into national monuments protected forever from commercial development or future mineral exploitation.
It was in the news at the end of the Obama administration after President Barack Obama created several national monuments, setting aside millions of acres on land and sea. At the time, some Republicans in Congress said they wanted to reform the act, which they said encouraged federal government overreach, a claim that has dogged the law since it was adopted.
President Theodore Roosevelt, who signed the Antiquities Act into law, created 18 monuments, including the Grand Canyon and Olympic National Park in Washington, totaling more than a million acres. According to data from the National Park Service, fifteen other presidents from both parties have designated a total of 170 national monuments, including marine monuments.
The president can make national monuments only from land already controlled by the federal government, and the act generally does not change how the land is used, said Lisa Dale, the associate director of the Yale Center for Environmental Law and Policy. If leases for mining, ranching, drilling or logging already exist on land to be made into a national monument, they can continue, but new leases probably won’t be allowed, she said.
Most legal scholars and historians agree that the Antiquities Act does not give the president the authority to revoke previous national monument designations, but a president can change the boundaries of a national monument. Congress can convert a national monument into a national park, which it has done many times.
Who could be hurt by possible changes?
Most Americans support protection of public lands. According to a 2016 study from Harvard’s Kennedy School of Government, more than 93 percent of respondents said that historical sites, public lands and national parks should be protected for current and future generations.
Char Miller, an environmental historian at Pomona College, said that if national monuments were diminished by the review process, it would actually hurt the people opponents of the law are claiming to protect.
Some designations are controversial, as was Mr. Obama’s designation of the Bears Ears National Monument in Utah in December. Republicans argued that it would hurt the local economy, but Mr. Miller said wilderness areas can bring in tourists who support local businesses.
Ryan Zinke, the interior secretary, said he would provide an interim review of the monuments in 45 days and would make specific recommendations about Bears Ears.
At three of the national monuments Mr. Obama created or expanded — Bears Ears, Katahdin Woods and Waters National Monument in Maine, and Papahanaumokuakea Marine National Monument in Hawaii — special effort was made to include Indian tribes in the designation process and continuing management of these areas.
Ms. Dale said that reducing these monuments or changing them “would have a chilling effect on tribal federal relations when it comes to protecting landscapes.”
Who would it help?
If existing national monuments are reduced in size, it could benefit extractive industries like oil and gas, mining, logging, as well as ranching, Mr. Miller said, because the government could grant more leases on federal land. Given the Trump administration’s recent actions — including lifting the moratorium on drilling on federal lands and the obligation to limit methane emissions on public lands — officials might be eyeing new fossil fuel leases on previously protected land, though Mr. Zinke said he was not predisposed to make any such recommendation about the monument land.
Mr. Zinke said that he has heard claims that some monument designations have ended in “lost wages, lost jobs and reduced public access.” But he added that he believed “some jobs probably have been created by recreational opportunities.”
Some of the opposition to the national monuments may be ideological. Western ranchers and sportsmen have long complained about what they see as federal land grabs that limit their access to millions of acres of public territory. However, a majority of Americans in Western states, home to vast tracts of federal land, support maintaining public land.
“No one loves their public lands more than I,” Mr. Zinke said. “You can love them as much, but not more than I do.”