List of national monuments of the United States

[1] Concerns about protecting mostly prehistoric Native American ruins and artifacts, collectively known as antiquities, on western federal lands prompted the legislation, which allowed the president to quickly preserve public land without waiting for legislation to pass through an unconcerned Congress.

President Theodore Roosevelt established the first national monument, Devils Tower in Wyoming, on September 24, 1906.

[4] Eighteen presidents have created national monuments under the Antiquities Act since the program began; only Richard Nixon, Ronald Reagan, and George H. W. Bush did not.

The five largest national monuments are all oceanic marine sites that protect waters and submerged lands where commercial fishing is prohibited.

Management practices vary across agencies and sites according to their missions, the size or type of protected place, and legal authorization.