National monument (United States)

In the United States, a national monument is a protected area created by proclamation of the president of the United States or by act of Congress. National monuments protect a wide variety of natural and historic resources, including sites of geologic, marine, archaeological, and cultural importance. The Antiquities Act of 1906 established the national monument designation and gave presidents the power to proclaim the creation of a national monument from any area owned or controlled by the federal government. In contrast, national parks in the U.S. must be created by Congressional legislation. Some national monuments were first created by presidential action and later designated as national parks by congressional approval.

The 138 national monuments are managed by several federal agencies: the National Park Service, United States Forest Service, United States Fish and Wildlife Service, the Bureau of Land Management, and the National Oceanic and Atmospheric Administration (in the case of marine national monuments). Historically, some national monuments were managed by the War Department.

President Theodore Roosevelt used the Antiquities Act to declare Devils Tower in Wyoming as the first U.S. national monument.