Arizona’s Verde Valley is home to an extensive exhibit of rock art that dates back 900 years. Among the 1,000 engravings and carved red sandstone figures are vivid expressions of distraught people, rich wildlife, and undulating lines.
Only recently, however, have locals noticed a curious feature on the largest and best-preserved section of petroglyphs in the valley, the B-Bar-B heritage site. On the day of the summer solstice, around June 21, shadows cast by two rocks fall on the petroglyph below, perfectly framing the carved images of a corn plant and a dancing figure with a sunbeam.
This precise light show occurs only on the longest day of the year, which is no coincidence. It is believed that this piece of rock art served as a calendar to mark the passage of the seasons, the beginning of spiritual ceremonies, and the time to begin planning the next season’s harvest.
Local archaeologist Kenneth Zoll talked to the Hopi, one of the Indian tribes that descended from the Sinagua people who created the art. They explained to him that the stones are specifically used to cast shadows, making the rays of sunlight appear to fall on certain images. This happens at certain times during the year, when each shadow and ray of sunlight creates a seasonal image for them that has cultural, social, or spiritual significance.
The 1,000 petroglyphs were carved in rock about 900 years ago by the Southern Sinagua people, a pre-Columbian culture that lived in the hot lands of central Arizona between about AD 500 and 1425. In addition to their distinctive carvings, they left behind a tremendous legacy of linguistics and folklore, as well as physical archaeological traces such as cliff dwellings and pit houses.
There are likely many more such solar calendars in the depths of central Arizona; however, the only real way to find them is to be in the right place at the right time.