Due in part to difficult terrain both locally and in surrounding provinces and the shortage of capital for rail construction, Yunnan remained outside of China's domestic rail network until 1966 when the Guiyang–Kunming Railway was completed. The line would not enter into operation until 1970, the same year that the Chengdu-Kunming was completed. The Nanning–Kunming Railway to Guangxi was completed in 1997, followed by the Neijiang–Kunming Railway in 2001.