National monument (United States)

National monuments protect a wide variety of natural and historic resources, including sites of geologic, marine, archaeological, and cultural importance.

The reference in the act to "objects of ... scientific interest" enabled President Theodore Roosevelt to make a natural geological feature, Devils Tower in Wyoming, the first national monument three months later.

In 1920, the United States Supreme Court ruled unanimously that the Grand Canyon was indeed "an object of historic or scientific interest" and could be protected by proclamation, setting a precedent for the use of the Antiquities Act to preserve large areas.

A bill abolishing Jackson Hole National Monument passed Congress but was vetoed by Roosevelt, and Congressional and court challenges to the proclamation authority were mounted.

In 1950, Congress finally incorporated most of the monument into Grand Teton National Park, but the act doing so barred further use of the proclamation authority in Wyoming except for areas of 5,000 acres or less.

The proclamation authority was not used again anywhere until 1996, when President Bill Clinton proclaimed the Grand Staircase–Escalante National Monument in Utah, after many years of unsuccessful advocacy by conservationists to protect parts of the area.

President Barack Obama significantly expanded two of them and added a fifth in the Atlantic Ocean, the Northeast Canyons and Seamounts Marine National Monument.

In December 2017, President Donald Trump substantially reduced the sizes of Bears Ears and Grand Staircase–Escalante National Monuments, removing protections on about 2.8 million acres of land where mining could resume.

[22][23][24] In 2025, Trump's interior secretary Doug Burgum ordered a review of all withdrawn public lands including national monuments for their exploitation for drilling and mining.