[1] The Sup'ung Line was opened along with the main line by the P'yŏngbuk Railway on 27 September 1939 to assist with the construction of the Sup'ung Dam.

[2] Following the partition of Korea, the line fell within the Soviet zone of occupation and was nationalised, along with all other railways in the zone, by the Provisional People’s Committee for North Korea on 10 August 1946.

[1] It subsequently became part of the Korean State Railway.

[3] Sup'ung Station, the terminus of the line, is served by six pairs of commuter trains operating on the Ch'ongsu—Sup'ung—P'ungnyŏn route.

A yellow background in the "Distance" box indicates that section of the line is not electrified.