The Ch'ŏngnyŏn Ich'ŏn Line is an electrified standard-gauge secondary mainline of the Korean State Railway running from P'yŏngsan on the P'yŏngbu Line to Sep'o on the Kangwŏn Line. The 141.3 km (87.8 mi) line is the southernmost of the three east-west transversal mainlines in North Korea.