PERIODS.

Earliest rock paintings were found to be 3,000 years old. They include those in Gyialing Mountain in northern Tibet and Alung Gully in western Tibet. Other rock paintings date from a period 3,000-2,000 years ago; they are concentrated in the western part of Tibet. Rock paintings of the later generation are represented by those found in dwelling caves on the bank of the Nam Co Lake in northern Tibet; they were most likely created during the Tubo Kingdom.
 
Tree Worshiping:Rock painting at Qugarchang,Ritog,Ngari.

Yaks stand conspicuously in what are described in rock paintings in Tibet, largely because yaks were much used for transportation purposes and were vital to Tibetan livelihood. As a kind of art form, however, rock paintings exaggerated the animals, especially in their back and horns. In some cases, the body of a yak was carved into the rock, with a large tail and small head, and highlighted by short yet strong legs. Their horns bend 180 degrees or even 360 degrees.
 
Yaks:Rock painting at Takang-ma and Nabulung in western Tibet.(The three above are rock painting in Takangma,and others below at Nabulung)

Rock paintings created in later period were not all chiseled out. The yak body becomes longer and comparatively thinner, with a small and pointed head. They adopt a running stance. Such rock paintings are found mainly in the western part of Tibet, mostly in Takaamba and Renmodong.

There are also yaks with rectangular-shaped body, small head, bent horn, and arched back. A salient feature is long, drooping hair on the belly. Though such yaks do not impress viewers with their running stance as seen in other rock paintings, their giant belly with drooping hair catches the viewers' attention. What is most interesting is that they bear symbols of the sun, the moon or the swastika.