After the 1949 Communist revolution, Hulunbuir was annexed into Inner Mongolia, but the region kept economic ties to the rest of the northeast via the Chinese Eastern Railway.[4] During the Cultural Revolution, the parts of historical Manchuria inside Inner Mongolia were briefly restored to their original provinces; Hulunbuir was given back to Heilongjiang from 1969 to 1979.[4] Until October 10, 2001, Hulunbuir was administered as a League. The area is 263,953 km2 (101,913 sq mi) and had a population of 2.710 million in 2004, The jurisdiction area of the city is larger than all but 8 Chinese province-level divisions (and 42 U.S. states), although the actual urban agglomeration is just a very small part of the region, and the average population density of the area is very low.
