These are very common throughout the Gorge. Pictographs are paintings. The colors were made from different minerals like iron oxide that produced red, a certain type of clay produced white, copper oxides produced blue-green, and charcoal and manganese oxide that produced black. These minerals were pounded into a powder and then mixed with a liquid such as water, blood, eggs, fat, plant juice, or urine. The paint would then be applied to the rock surface with fingers or brushes made of animal hair, twigs or feathers.
Petroglyphs are rock engravings.
The engraving is made in one of two methods. Pecking is where a hard stone is used to slowly peck away portions of the rock surface or abrading the surface of the rock with another harder stone. The exact purpose of these rock drawings is unknown. Some say that they were done for religious ceremonies. Some say that they are a record of Indian history.