Painted Rock Petroglyph Site, Archaeological site with petroglyphs in Maricopa County, United States

Painted Rock Petroglyph Site holds about 800 pecked images on weathered basalt boulders overlying a granite outcrop. The outcrop is an east-west oval roughly 400 feet long and 20 feet tall with two small knob tops. Most carvings cluster on boulders along the eastern edge, facing all directions; designs include curving lines, geometric patterns and concentric circles.

Hohokam farmers lived beside the Gila River here, and their village ruins of the Pioneer, Colonial and Sedentary-Classic periods lie to the north, west, south and east of the outcrop. Later travellers carved their own inscriptions: Juan Bautista de Anza passed in 1775-1776, followed by the Mormon Battalion in the 1840s and the Butterfield Overland Mail. The site was listed on the National Register of Historic Places in 1977.

The name "Painted Rock" comes from the lighter tan carvings that stand out against the dark basalt. The site lies at the western edge of the Hohokam cultural area, so its designs mix Hohokam traits with Patayan ones from farther west. Historic travellers left their own inscriptions beside the ancient images: Juan Bautista de Anza's 1775–1776 expedition passed nearby, as did the Mormon Battalion in the 1840s and the Butterfield Overland Mail.

The petroglyphs sit on the eastern edge of a low granite outcrop reached by paved roads and a walking trail with informational signs. The nearest water is the Gila River; summer daytime temperatures exceed 100 °F (40 °C) from May to October, and annual rainfall is about 6 inches (150 mm). There is no public access to Painted Rock Dam or the former Lake Unit.

Besides ancient Hohokam designs, the boulders carry historic graffiti: inscriptions left by Juan Bautista de Anza's 1775-1776 expedition, the Mormon Battalion in the 1840s, Butterfield Overland Mail stages and later pioneers. General George Patton also used the area as a tank-training headquarters during World War II.