Perhaps a thousand years ago, someone climbed to the cliff face above with a stone tool and chipped into a mineral-darkened area of sandstone until the image of a bighorn sheep began to take shape. The Fremont people, who lived in the Dinosaur area between 550 and 1200, created these petroglyphs, patterns or figures chipped or carved into rock. Archaeological evidence indicates that the Fremont were in the area for about 600 years, but their fate is unclear. Drought, the arrival of a new group of people, or a change in lifestyle after mixing with other cultures may explain why they can no longer be traced as a distinct culture in the archaeological record after about 1200.