The Colorado Millennial Site in southeastern Colorado, near Ruxton on the border of Baca and Las Animas counties, preserves an unusually long record of human use from about 6999 B.C. to A.D. 1900. Known also as Hackberry Springs and Bloody Springs, it occupied a sheltered spot beneath an overhanging bluff with a dependable water source that drew repeated habitation and activity. Evidence there includes remains from Archaic and Woodland cultures, prehistoric rock art, traces of village settlement, and a later battle site. In 1868, Cheyenne fighters and the U.S. 7th Cavalry fought here in what is identified as the last documented military battle with Native Americans in southeastern Colorado.