[2] Originally called the Hamnam Line, it was built by the privately-owned Chosen Magnesite Development Railway (Japanese: 朝鮮マグネサイト開発鉄道 Chōsen Magunesaito Kaihatsu Tetsudō, Korean: 조선 마그네사이트 개발 철도; MR: Chosŏn Magŭnesaitŭ Kaebal Ch'ŏldo), to exploit the magnesite deposits of the Kŏmdŏk district; the company was granted a licence to operate passenger trains on 25 March 1943.

[3] The first section, 27.7 km from Yŏhaejin on the P'yŏngra Line to Tongam, was opened on 30 March 1943, followed by a 32 km extension from Tongam to Ryongyang (nowadays called Paekkŭmsan) that was opened on 4 December of the same year.

[3][4] After the partition of Korea following the end of World War 2 and the subsequent establishment of the DPRK, the line was nationalised and its name was changed to the current name.

[2] The final 20 km (12 mi) extension from Kŭmgol to Muhak was built after 1988.

Northbound traffic is mainly coal, construction materials, foodstuffs and empty cars for ore-loading.