The park's website says this about the early human history in the area:
"The earliest artifacts identified within BBRSP indicate that Native Americans traversed the area as early as perhaps 11,000 years ago, and continued to do so well into the 19th century. Native American site types attributable to the prehistoric era include open campsites, open camps associated with rock shelters, rock shelters, quarries, lithic scatters, Late Prehistoric Cielo complex (ca. A.D. 1250-1680) sites, rock art sites (primarily pictographs, or rock paintings) and special-use or ritual sites."
"Many pictographs that have been recorded within the Park are monochromatic red, black, or white. Bichrome and polychrome (red, black, yellow, white) figures also occur. The figures include humans, animals, insects, tally marks, double zigzags, hourglass chains, star patterns and various other abstract motifs. Most of these pictographs were probably painted during the Late Archaic (ca. 1000 B.C. - A.D. 1000) or Late Prehistoric (A.D. 1000 - 1535) periods. Other pictographs represented by human figures on horses, longhorn cattle, Spanish saddles and crosses date to the Protohistoric (ca. A.D. 1535-1700) period or later."
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