What Is the Antiquities Act, and How Is the 120-Year-Old Law Being Tested by Trump?

President Donald Trump signed two proclamations Monday, dramatically reducing the size of two national monuments in Utah and reviving a long-running legal dispute over the limits of presidential authority under the Antiquities Act of 1906.

The proclamations reduced by 90% the protected areas of Bears Ears and the Grand Staircase-Escalante. 

Bears Ears is a pair of symmetrical buttes that dominate the horizon in southeast Utah. The monument spanned some 1.36 million acres before Trump reduced it to 131,100. The Grand Staircase-Escalante is a set of step-like sedimentary layers that connect to the rim of the Grand Canyon. Trump reduced the monument from some 1.87 million acres to 181,500. 

Together, the two presidential proclamations could open up more than 3 million acres of formerly protected land—including sacred tribal sites—to exploration for oil, minerals, and gas, as well as motorist and non-motorist recreation.

Preservation advocates and tribal representatives have criticized the changes, while suggesting that greater cooperation between the federal government and tribal leadership is required.

The Bears Ears Inter-Tribal Coalition—which includes the Hopi Tribe, Navajo Nation, Ute Mountain Ute Tribe, Pueblo of Zuni, and Ute Indian Tribe—said that the sites contain “thousands of sacred cultural sites and important areas of spiritual significance.” 

In a press release shared Tuesday, the coalition wrote, "Tribal Nations understand Bears Ears as an interconnected living cultural landscape, where the land itself—and the relationships among its cultural sites, waters, plants, animals, and sacred places—are what must be protected."

The coalition originally advocated for the designation of national monument status, which was granted by President Barack Obama in 2016. It then sued the Trump Administration in 2017 for attempting to resize the monument, though the case was suspended when President Joe Biden restored its original boundaries in 2021—and expanded the site by 12,000 additional acres. 

The coalition has since said that the governments it represents, going forward, require “a meaningful voice in the development of a land management plan” for Bears Ears.

“President Trump’s outrageous attack on Grand Staircase-Escalante and Bears Ears national monument was taken at the urging of Utah politicians,” Scott Braden, the Executive Director for the Southern Utah Wilderness Alliance (SUWA), said in a statement. “These two landscapes deserve to be protected for current and future generations of Utahns and Americans, not opened to exploitation.” 

The SUWA expressed plans to contest the proclamations in court.

The Wilderness Society also criticized the proclamations, accusing the administration of ignoring "the voices of Tribal Nations, local communities, and the millions of Americans who want these places protected for future generations,” according to a statement from its president, Tracy Stone-Manning, who was the Director of the Bureau of Land Management under Biden.

Utah politicians, however, expressed support for the measures, which returns the affected lands to their prior federal management status. 

“For too long, presidents have weaponized monument designations to lock up millions of acres, close roads, restrict grazing, and cut rural communities off from lands their families have lived on and worked for generations,” Republican Sen. Mike Lee said in a statement on Monday. 

Republican Governor Spencer Cox, who was present at the White House when the proclamations were signed, wrote on X that “the question has never been whether to protect Bears Ears and Grand Staircase-Escalante national monuments, but how to protect them best.”

He continued: “We deeply value these natural, cultural, and scientific treasures. The historic landmarks and other nationally significant resources remain under federal protection, while allowing agencies to direct limited resources toward caring for these specific sites rather than millions of surrounding acres.”

Trump’s proclamations challenge the limits of presidential authority when it comes to managing public lands, with implications that extend far beyond Utah. At the heart of the debate is the Antiquities Act of 1906.

What Is the Antiquities Act?

Unlike national parks, whose designations must be approved by Congress, national monuments are given that status by the sitting president under the Antiquities Act. It was signed into law by President Theodore Roosevelt in 1906. 

The Congressional Research Service (CRS) said ​​that the Antiquities Act has been used by 18 U.S. Presidents to establish 168 protected areas, including marine monuments. President Bill Clinton established Grand Staircase-Escalante in 1996, two decades before Obama established Bears Ears. 

While presidents have frequently used the Act to enlarge existing monuments, Trump is the first President since John F. Kennedy to reduce the scale of a monument. Several earlier presidents—including William Howard Taft, Woodrow Wilson, Calvin Coolidge, Franklin Delano Roosevelt, Harry S. Truman, Dwight D. Eisenhower, and John F. Kennedy—also reduced monument boundaries. However, Trump's reductions are unprecedented in scale and may therefore face greater legal scrutiny.

The legal debate centers on the fact that while the Antiquities Act expressly authorizes presidents to establish national monuments, it does not explicitly address whether later presidents may shrink or abolish them. 

“My position has long been that the president does not have that authority,” Mark Squillace, professor of law at the University of Colorado Law School, tells TIME. “If you read the statute, the Antiquities Act, it specifically gives the president the authority to reserve monuments that contain historic objects and of scientific interest, but it does not give the president the authority to modify or revoke monuments that have been declared by prior presidents.”

He says that it’s important to look at the exact wording included in the text, because there are contemporaneous laws that specifically give the president those kinds of authority—for example, the 1897 Organic Administration Act's amendment to the Forest Reserve Act, which expressly says the President may "revoke, modify, or suspend" national forest proclamations and "reduce the area or change the boundary lines."

“So the argument is simply that when Congress wants to give the president broader authority, it has specifically done so,” Squillace says. 

The Act’s exact language has been carefully scrutinized over the years. Of particular note is the line that says national monuments must be limited to the “smallest area compatible with proper care and management of the objects to be protected.”

The Trump Administration alleges that both Clinton and Biden sought to protect a sweeping landscape that overly broadened the scope of the legislation as it is written.

“Where the President determines that the structures and objects identified by a prior monument proclamation no longer are, or never were, deserving of the Antiquities Act’s protections, the Antiquities Act permits the President to remove land from the monument and return it to its prior federally managed status,” Trump wrote in a proclamation on Monday.

He also wrote that the previously established Bears Ears National Monument “suffers from several flaws under Antiquities Act analysis” and that “generic” features “are not historic landmarks, historic or prehistoric structures, or other objects of historic or scientific interest.” The proclamation also argues that the Bears Ears region “contains several resources that are vital to energy and resource independence and, in turn, critical to national security.” 

Similarly, a proclamation for the Grand Staircase-Escalante says that the region contains resources that are “essential to important sectors of the economy of the United States, including defense, manufacturing, and transportation.” It also says that most of the areas around the monument are “already adequately protected by Federal law and do not require a reservation of land under the Antiquities Act for protection.”

Historically, courts have upheld broad presidential authority to grant monument status under the Antiquities Act, but they have not definitively ruled on a President’s power to revoke or reduce that designation.

Were it to advance through the courts, however, Squillace believes that the text of the statute would stand on its own. “This particular Supreme Court has been very narrow in its interpretations about delegations of power, and has made clear that the authority to delegate power is limited by the specific text of the law,” he says.