Plains Indian Rock Art by archaeologists James Keyser and Michael Klassen describes the origins, diversity, and beauty of Plains rock art. The region stretching from northern Colorado to southern Alberta and from the Rockies to the western Dakotas is the land of the Cheyenne and the Blackfeet, the Crow and the Sioux. Its grasslands and river valleys have nurtured human cultures for thousands of years. On cave walls, glacial boulders, and riverside cliffs, Native people recorded their ceremonies, vision quests, battles, and daily activities in the petroglyphs and pictographs they created on stone surfaces. Some sites were clearly intended for communal use; others clearly mark the occurrence of a private spiritual encounter. Elders often used rock art, such as complex depictions of hunting, to teach traditional knowledge and skills. Other sites document the medicine powers and deeds of important warriors. Some Plains rock art goes back more than 5,000 years; some forms were made continuously over many centuries. Images include humans, animals, weapons, masks, mazes, handprints, finger lines, geometric and abstract forms, tally marks, hoofprints, and the wavy lines and starbursts that humans universally associate with trancelike states. This 2001 volume explains rock art forms, techniques, styles, terminology, and dating; and offers interpretations of images and compositions.