North Eastern Coalfields is a unit of Coal India (CIL) operating in states of Assam, Meghalaya, Nagaland and Arunachal Pradesh.  North Eastern Region consists of seven states; only Assam, Meghalaya, Arnachal Pradesh and Nagaland are endowed with moderate coal reserves.

Though the coal occurrences are reported from four states of North Eastern Region, the actual coal exploitation activity is confined to states of Assam (Margherita Area) and Meghalaya (Simsong U/G) only.

NEC coal is of Tertiary age (Eocene to Oligocene= 40-55 million years) younger compare to deposits found in the Bihar, Jharkhand belt, attain low maturity of sub-bituminous coal rank with high calorific heat value ranging between 6500-7500 k.cal/kg.(Grade = A )
Although North Eastern Coalfields contains meager quantity of mineable coal reserves, is one of the country�s best coalfields having good quality coal characterized by very low ash content, high sulphur, high volatile matter and high caking index. Hence has got high demand for coal liquefaction plant and as blendable coal in steel industry.

In the year 1870 coal mining development activity was initiated by Dr.John Berry White, Civil Surgeon and Mr.George Turner, Mining Engineer in Assam.The first colliery Ledo Underground mine was opened in the year 1882 by M/s.Assam Railways & Trading Company Ltd. in the North Eastern Region .

Subsequently, more collieries were opened to meet the demand of coal from this region.
In the beginning of 19th Century the coal production was 30% of the total country�s output, which now stands nearly at 0.37% only (1.05MT) against total 360.94 MT of Coal India.

Out of total 257 BT Indian coal reserves , only 0.94 BT occur in the North Eastern Region which constitutes 0.37% share of Indian coal reserves (up to 1200 m. depth and as on 01.01.2007).
After nationalization, the mining operations were confined to Makum and Dilli-Jeypore Coalfields of Margherita Area in Assam. At present there are five working mines 3(Three) underground and 2(Two) opencast mines.

In 1995, Namchik mine was surrendered to State Govt. Arunachal Pradesh for want of Forest Clearance.The activity of exploratory mining at Simsong in Meghalaya was suspended. Since 1999, due to problems in mining activity and insurgency.