Montezuma County is the southwesternmost of the 64 counties in the U.S. state of Colorado. As of the 2010 census, the population was 25,535. The county seat is Cortez.Mesa Verde National Park, Canyons of the Ancients National Monument, Yucca House National Monument, and Hovenweep National Monument preserve hundreds of ancient Amerindian structures, including the famous cliff-dwellings, found in the county.