A recently published U.S. Justice Department memo has sparked concerns among conservation organizations as it potentially paves the way for President Donald Trump to roll back protections on millions of acres of federal lands and oceans. The 50-page legal opinion focuses on the Antiquities Act, stating that Trump has the authority to abolish or reduce the size of national monuments established by previous presidents, including those set up by President Joe Biden earlier this year in California.

Critics have described the memo as “blatantly politicized” and a threat to over 13.5 million acres of national monuments. The opinion has raised fears of unraveling national monuments and undermining the Antiquities Act, a fundamental conservation law granting presidents the power to safeguard lands of historical, cultural, and scientific significance.

Since his 2024 election victory, Trump has been keen on removing barriers to energy resource exploration and production on public lands. The memo’s implications align with Trump’s previous actions, such as reducing the size of Utah monuments and opening up federally managed ocean waters for drilling.

The controversy surrounding the Antiquities Act stems from differing views on presidential powers, with proponents arguing it allows swift protection of vulnerable lands while opponents criticize it for federal overreach and hindering natural resource use. If Trump acts on the memo, conservation groups warn of significant risks to landscapes, Native American sites, protected species, and habitats across federal lands, with numerous national monuments potentially losing their protections.