Details of figures and symbols from a rock-art panel discovered on canyon walls. Many of the images suggest figures of humans and animals.

She says that knowing what became "before" and "after" is important to archaeological investigation. Without it, we cannot demonstrate that various items, events, or ideas at a given place are related. She is able to date rock art by matching types of images to pottery design, and other items that can be dated.

The color of images pecked in the rock can also provide information. Because rock darkens over time, rock art that is darker and harder to see is usually older. Where there are overlapping images, Cole can compare the coloring, and determine how much age difference there is between them.

Many of the images — human figures, animals — we can recognize. But other patterns are mysterious. No one knows for sure what they represent. Some of the rock-art panels may tell stories of migrations or record spiritual events. Other images may indicate hunting activities. Rock art was also used to monitor the sun's position at different times of year. It was a way for ancient Native Americans to keep track of seasons, and know when to start planting.

Archaeologists, historians, and modern Native Americans frequently disagree about the meanings of the images. Whatever the interpretations, the rock makes us think and wonder about the drawings, and who the people were that created them.

Photo Credits: Kenneth Benson