Jiuzhaigou lies at the southern end of the Minshan mountain range, 330 km north of the provincial capital of Chengdu. It is part of the Jiuzhaigou County (formerly Nanping County) in the Aba Tibetan Qiang Autonomous Prefecture of northwestern Sichuan province, near the Gansu border.
The valley covers at least 240 km², with some protection organizations giving the area as 600 to 720 km², with buffer zones covering an additional 400 to 600 km². Its altitude, depending on the area considered, ranges from 1,998 to 2,140 m (at the mouth of Shuzheng Gully) to 4,558 - 4,764 m (on Mount Ganzigonggai at the top of Zechawa Gully).
The remote region was inhabited by various Tibetan and Qiang peoples for centuries, but was not officially discovered by the government until 1972. Extensive logging took place until 1979, when the Chinese government banned such activity and made the area a national park in 1982. An Administration Bureau was established and the site officially opened to tourism in 1984; layout of facilities and regulations were completed in 1987. The site was inscribed by UNESCO as a World Heritage Site in 1992 and a World Biosphere Reserve in 1997.
Since opening, tourist activity has increased every year: from 5,000 in 1984 to 170,000 in 1991, 160,000 in 1995, to 200,000 in 1997, including about 3,000 foreigners. Visitors numbered 1,190,000 in 2002. As of 2004, the site averages 7,000 visits per day, with a quota of 12,000 being reportedly enforced during high season. The Town of Zhangzha at the exit of the valley and the nearby Songpan County feature an ever-increasing number of hotels, including several polished five-stars.
Jiuzhaigou's landscape is made up of high-altitude karsts shaped by glacial, hydrological and tectonic activity. It lies on major faultlines on the diverging belt between the Qinghai-Tibet Plate and the Yangtze Plate, and earthquakes have also shaped the landscape. The rock strata is mostly made up of carbonate rocks such dolomite and tufa, as well as some sandstone and shales. The valley includes the catchment area of three gullies (which due to their large size are often called valleys themselves), and is one of the sources of the Jialing River, part of the Yangtze River system.
Jiuzhaigou's best-known feature is its dozens of blue, green and turquoise-colored lakes. The local Tibetan people call them "Haizi" in Chinese, meaning "son of the sea". Originating in glacial activity, they were dammed by rockfalls and other natural phenomena, then solidified by processes of carbonate deposition. Some lakes have a high concentration of calcium carbonate, and their water is very clear so that the bottom is often visible even at high depths. The lakes vary in color and aspect according to their depths, residues, and surroundings. Some of the less stable dams and formations have been artificially reinforced, and direct contact with the lakes or other features is forbidden to tourists.