The northern Garhjat hills are a part of the Chotanagpur plateau while the southern part is an extension of the Eastern Ghats and can be divided into three - the northern uplands, the Mahanadi valley, and the south-western hills. The important rivers that drain the Garhjat hills are the Brahmani, the Mahanadi, the Baitarani and the Subarnarekha. The Odisha Highlands are densely forested with tropical semi-evergreen and tropical dry and moist deciduous forests. The Scheduled Tribes account for as much as 37% of the regions population and the Gonds are a major tribal group of this region. Malaria is a major public health concern in these hills.