The Antiquities Act of 1906 gave the President authority to designate national monuments. This Act specifies that the purpose of monuments is to protect “objects of historic or scientific interest.” Congress can also establish monuments by passing laws to protect certain natural or historic features. BLM Colorado has one National Monument:

CANYONS OF THE ANCIENTS NATIONAL MONUMENT and the Anasazi Heritage Center manage the highest known density of archaeological sites and the most studied archaeological landscapes in the nation. The Heritage Center is a world-class museum and the headquarters for the 166,000-acre monument. Visitors should come to the Heritage Center first to learn about Ancestral Puebloan culture and how to explore the area’s fragile resources. There is a range of experiences visitors can enjoy, from visiting the developed Lowry Pueblo to exploring the more remote Painted Hand Pueblo.  The six-mile Sand Canyon Trail is a favorite spot for hiking. Canyons of the Ancients National Monument and the Anasazi Heritage Center are located in Southwestern Colorado.