The topography of Bihar can be easily described as : (i) a fertile alluvial plain occupying the north, the Gangetic Valley; and (ii) a rocky, incredibly mineral rich plateau in the south, the Chhotanagpur Plateau. The northern plain extends from the foothills of the Himalayas in the north to a few miles south of the river Ganges as it flows through the State from the west to the east. The Chhotanagpur plateau occupies roughly 1/3rd of the south, extending up to the southern border with Orissa.
Rich farmland and lush orchards extend throughout the north. Following are the major crops: paddy, wheat, lentils, sugarcane, jute (hemp, related to the marijuana plant, but a source of tough fibers and "gunny bags".) Also, cane grows wild in the marshes of West Champaran.The principal fruits are: mangoes, banana, jack fruit and litchis. This is one the very few areas outside China which produces litchi. There is very little industry in the plain region except for the sugar factories that are scattered all over the northern plains, particularly in the western region. Jute is transported to the jute factories located mostly in Calcutta.
The southern plateau is among the world's richest source of mineral. Principal products are: coal, iron ore, bauxite, copper, and mica. For mica, Bihar is perhaps the only source, confined mostly to the districts of Hazaribagh and Giridih. This mineral was valuable in the manufacture of windshields for airplanes and automobiles due to its transparent and non-shattering property. With the invention of synthetic materials, the commercial value of mica has declined.
Bihar is the single most important source for coal, iron ore and bauxite in India.
The south is also a forested area. People belonging to many tribal groups live in the forests of Chhotanagpur and Santhal Parganas. (Please see under the"People" section.)
Among the wildlife, notable are: deer, bears, numerous species of birds, including the peacock, pheasant, and wild fowl, and most notably, the tiger. The forest around Hazaribag is one of the last remaining refuge of this highly endangered species.
The forests of Bihar yield valuable commercial products besides the timber. Leaves of some trees are used in the manufacture of an indigenous product for smoking, i.e., the bidi. A resinous material secreted by the lac insect is valuable commercially. It is the source of shellac. Also, bangles made of lac are very popular among women of Bihar. The silkworm is the source of magnificent silk - characteristically, the tusser or tussah silk.
The majestic banyan tree (Ficus bengalensis), and the related pipal (Ficus religiosa), dot the entire landscape of the State.