The President of the United States derives the authority to create national monuments from the Antiquities Act of 1906. This landmark legislation was signed into law by Theodore Roosevelt to protect "historic landmarks, historic and prehistoric structures, and other objects of historic or scientific interest" located on federal lands. The Act allows the President to issue executive proclamations to bypass the often lengthy Congressional approval process for national parks, ensuring that threatened cultural or natural resources can be protected immediately. While the Act specifies that the reserved areas should be "confined to the smallest area compatible with proper care and management," various presidents have used it to protect millions of acres, leading to significant legal and political debates over federal land use. Despite these challenges, the Antiquities Act remains the primary tool for executive conservation, having been used to establish iconic sites like the Grand Canyon (originally a monument) and the Bears Ears National Monument.