The Bakhtiari tribe, which numbers more than 800,000, inhabits an area of approximately 67,000 sq. km (25,000 sq. mi) that straddles the central Zagros Mountains in Iran. Although only about a third of the tribe is nomadic (the rest are settled agriculturists), the nomads embody the Bakhtiari cultural ideals. They specialize in producing meat and dairy products and migrate seasonally with their sheep, cattle, or goat herds from high plateau pastures, where they spend the summer, west of the city of Esfahan, to lowland plains in the province of Khuzistan for winter herd grazing. Their migration is among the most spectacular known among nomadic paternalists anywhere. They are obliged to cross mountain passes at about 3,050 m (10,000 ft) and therefore have to time their movement with extreme care in order to minimize the danger of early snowfall, flooding mountain rivers, and lack of grazing. Traditionally these dangers took a heavy toll, but in recent years the government has helped the migration by building bridges, improving the route, and setting up fodder supplies en route.
The Bakhtiari speak a dialect of Persian called Lori and are Shiite Muslims. Politically the tribe used to form a confederacy under a chief appointed by the shah, but this position has now been abolished. The confederacy was most effective in the late 19th and early 20th centuries, and the Bakhtiari played an important role on the national level in Iran’s constitutional movement. More recently many tribesmen have left the traditional way of life for employment in the oil industry in the cities.
There are three main zones in the Zagros system. The region north of a line formed by the road Qazvin, Hamadan, and Kermanshah. South-east is the area generally spoken of as Loristan. This area is characterized by intensively folded mountains in the north, opening up to the south.
Loristan has historically been divided into Lor-i Kuchek (the small Lor), west of the Ab-i Diz, and Lor-i Bozorg (the big Lor), the Bakhtiari mountains.
The two major divisions of Lor-i Kuchek are the zones west of Kabir Kuh mountain (or west of the Saimarreh river), called Posht Kuh (behind the mountain), and Pish Kuh (in front of the mountain).
Posht Kuh is formed by two ranges, the outer which reaches a height of 1800m. forms a distinct barrier to penetration from the west. The Saimarreh river basin, dividing the peoples of Posht Kuh and Pish Kuh is a long grassy valley surrounded by high continuous ridges.
Pish Kuh to the north east of Posht Kuh, is bordered on its north-east by the Borojerd valley, on its south by the alluvial plain of Khuzestan.
The Pish Kuh may also be divided into two main sub sections, one east of the Kashgan river and west of the Ab-i Diz,known as Balgariwa; and the region to the north- west of the Kashgan, the Pish Kuh itself.
Lor-i Bozorg is the region of the Bakhtiari Mountains. It is the region east of the Ab-i Diz and north-west of the Khersin river. To the south-west is Khuzestan and the Iranian Central Plateau is to the north.