Scholars examine the legal limits on presidential power to reduce protections for federal lands and waters.

This past summer, President Donald Trump exercised the Antiquities Act of 1906 to reduce protections across millions of acres of federal lands and waters, reviving a longstanding debate over the President’s authority under the statute.

In June, President Trump modified the proclamations establishing and expanding the Papahānaumokuākea, Mariana Trench, and Rose Atoll Marine National Monuments to allow commercial fishing in portions of each monument. The proclamation opened hundreds of thousands of square miles to fishing but left some existing restrictions intact. The following month, President Trump reduced Bears Ears and Grand Staircase-Escalante National Monuments in Utah by more than 90 percent, sparking federal lawsuits led by environmental conservation groups and tribal nations alike.

These actions build on President Trump’s first-term reductions of the same Utah monuments, which President Biden had restored in 2021—a cycle of reversals that leaves unresolved a central question about the scope of the Antiquities Act. The Act authorizes Presidents to designate federal lands containing “objects of historic or scientific interest” as national monuments and requires reservations to remain within the “smallest area compatible” with protecting those objects.

The statute does not, however, expressly authorize presidents to revoke or reduce monuments established by their predecessors. Interpretations differ. In a May 2025 opinion, the Office of Legal Counsel concluded that the Antiquities Act permits a President to alter prior monument designations, including eliminating land associated with a monument. The Attorney General reached the opposite conclusion in a 1938 opinion. Legal scholars have largely supported the latter view because the 1938 opinion was issued closer to the Act’s enactment.

The Trump Administration argues that presidents can determine whether land protected under the Antiquities Act no longer qualifies for monument status. Critics argue that the statute grants authority only to protect federal lands, not to dismantle those protections.

The 2026 national monument reductions have raised additional disputes. Bears Ears, for example, emerged from a proposal by five Tribal Nations seeking federal protection and a role in managing their ancestral lands, making President Trump’s July 2026 proclamation a challenge not only to the scope of presidential authority under the Antiquities Act, but also to a public-land management arrangement built through years of tribal advocacy and federal-tribal cooperation. President Trump’s June modification of the proclamations governing Papahānaumokuākea, Mariana Trench, and Rose Atoll Marine National Monuments reignites controversy over whether the Antiquities Act applies to ocean waters. Fishers argue for a stricter interpretation of the term “land [owned or controlled by the Federal Government]” that would preclude presidential authority to establish marine national monuments. Federal courts, however, have repeatedly concluded that marine national monuments fall within the Act.

In this week’s Saturday Seminar, scholars explore the Trump Administration’s rollback of U.S. public land and water protections through presidential proclamations.

• In a Vanderbilt Law Review note, Chick Hallinan of Vanderbilt University Law School considers whether, in enacting the Antiquities Act, Congress sought to delegate to the President the power both to declare national monuments and to modify or revoke their status. Hallinan explains that, although the Act authorizes the President to declare national monuments, its language does not similarly grant authority to modify or revoke monuments. Some scholars argue that because the Constitution grants plenary authority to Congress over public lands, the narrow text of the statute limits the President’s authority, Hallinan notes. Despite the plausibility and appeal of this argument, Hallinan concludes that because presidents have altered monument boundaries without judicial intervention, the Act’s history undermines this formalistic reading.
• In a Journal of Institutional Economics article, Jordan Lofthouse, a senior research fellow at the Mercatus Center at George Mason University, examines how Presidents from both parties have used their broad discretion under the Antiquities Act when making national monuments decisions. Lofthouse provides a history of how nearly all Presidents since Theodore Roosevelt have created, enlarged, or reduced national monuments. He argues that Presidents may use the Act to gain electoral advantages to themselves or members of their parties, advance other policy goals through political exchanges, or strengthen their legacies. Lofthouse uses case studies of recent Presidents to illustrate how these incentives shape the use of the Act.
• In a Tulane Environmental Law Journal working paper, Michael C. Blumm, Tory Dille, and Reese Southworth of Lewis & Clark Law School provide a chronological overview of environmental law before and during the Trump Administrations, focusing on how actions during both Administrations unraveled Democratic-era national monument protections. Blumm, Dille, and Southworth identify the rescission of specific monuments designations, directives to streamline permitting and consultation requirements, cuts to federal land management agencies, and executive orders encouraging the use of federal lands and waters for drilling, natural gas production, and logging. These deregulatory efforts represent an “unprecedented and astonishing” departure from the preceding 50 years of environmental law, Blumm, Dille, and Southworth argue.
• John Leshy of the University of California College of the Law, San Francisco argues in an article published by the George Wright Society that S. public land management has broad bipartisan support but faces privatization threats. Leshy contends that, over the past 50 years, the Bureau of Land Management (BLM), which oversees the most acreage, has increasingly emphasized conservation and permanent public ownership. Leshy explains that both Trump Administrations have pursued policies favoring industrial development on public lands, although the second has largely avoided direct efforts to transfer federal lands to private ownership. Leshy warns that weakening the Bureau could reduce the agency’s effectiveness and public support.
• In an article for Transatlantica, Nathalie Massip of Université Côte d’Azur explains that Bears Ears National Monument is a landmark development in collaborative conservation efforts between the United States and Native American Tribes. Massip describes that in 2015, five Tribal Nations petitioned the Obama administration to use the Antiquities Act to protect lands sacred to them and sought an active role in managing the monument. She contends that this effort marked a significant development in conservation. According to Massip, this collaboration is under threat from the Trump Administration’s efforts to shrink Bears Ears and reduce the tribes’ management role. Massip argues that, regardless of Bears Ears’ fate, conservation laws such as the Antiquities Act can support further federal-tribal collaborative conservation.
• In an essay in the forthcoming Federalism in a Divided America, Elliott Finn of the Bren School of Environmental Science & Management at the University of California, Santa Barbara, and several coauthors examine attitudes toward public land management and frame the Trump Administration’s anti-public land policy. The Finn team contends that decades of poor decision-making over public lands bred resentment, particularly in rural communities. Finn and his coauthors explain that policy conflicts between environmental conservationists acting through federal institutions and rural communities have contributed to “governance nostalgia,” a desire among rural Western communities to return to a premodern relationship with public lands. The Finn team concludes by advocating a collaborative and place-centric approach to public land management that incorporates local voices.