Wall ruins in the Canyon of the Ancients National Monument -- one of the nation's newest national parks or monuments -- in southwestern Colorado's Montezuma County. The archaeologically-significant landscape's 176,056 acres are overseen by the Bureau of Land Management to conserve, protect, and restore these nationally significant lands. With them are three installations of the National Park Service-managed Hovenweep National Monument. Photo by Carol Highsmith, 2016.