The Nine Mile Canyon in eastern Utah, in the United States, is home to one of the largest concentration of native American rock art in North America. More than one thousand rock art sites has been identified in this area, with a conservative estimate of ten thousand individual engraving, but some archeologists suspect the actual numbers are more then ten times higher. It has been called "the world's longest art gallery".

The Nine Mile Canyon is actually 40 miles long, and was carved by the Nine Mile Creek, a small river that flows into the Green River. The name comes from the map of early explorer John Wesley Powell's cartographer, who did a nine-mile triangulation drawing while mapping the region.

Photo credit: Bureau of Land Management/Flickr

Most of the engravings and pictographs in the canyon walls were made by the Fremont Indians, who made Nine Mile Canyon their home as early as 300 AD. The early Fremont people were nomadic, moving from place to place foraging wild food and growing corn. By 750 AD, village life had developed with a number of farming villages consisting of semi-subterranean timber and mud pithouses. The rock art were done between 950 AD and 1250 AD, at the height of the Fremont culture. By 1500 AD, the indigenous culture had vanished. The exact reasons for this disappearance are not known. It is believed that the more aggressive Ute, Paiute and Shoshoni people drove them out of the region.

The rock art as well as other ancient artifacts such as rock dwellings and granaries are now protected by law, although the rock art is still vulnerable to natural erosion and dust created by increasing vehicular traffic.

Photo credit: T.Larson/Flickr

Photo credit: jimmy thomas/Flickr

Photo credit: jimmy thomas/Flickr

Photo credit: jimmy thomas/Flickr

Sources: Wikipedia / www.blm.gov / climb-utah.com