On March 2, Dongshan Tunnel, a key control project on the Suqi Highway (from Sunan Yugur Autonomous County of Gansu Province to Qilian County in Qinghai Province) along G213 National Highway, was successfully completed, marking the completion of the passageway linking Gansu and Qinghai along the Belt and Road. Construction of the tunnel is undertaken by China Tiesiju Civil Engineering Group.

The Suqi Highway stretches 62.769 kilometers in length. It starts at Baizhuangzi north of Sunan County and connects with Qinghai Provincial Highway S215, crossing the Qilian Mountains. China Tiesiju Civil Engineering Group is responsible for the construction of the Suqi 5 standard pipe section which measures 15.01 kilometers and includes roadbeds, bridges, and mountain culverts. The Dongshan Tunnel in this section is 3,639 meters long.

The tunnel is located in an alpine region at an average altitude of more than 4,000 meters above sea level deep in the Qilian Mountains in the northeastern part of the Qinghai-Tibet Plateau. For constructors, the control project was the most difficult one on the Suqi Highway. They had to overcome many challenges such as anoxia, the cold weather, difficulties in material transportation and frequent rain and snow. (Source: China Tiesiju Civil Engineering Group)