From Xi 'an, Shaanxi to Dunhuang, Gansu, starting from Dongdao West, the prefecture-level cities passing through are: Baoji, Tianshui, Dingxi, Lanzhou, Wuwei, Jinchang, Zhangye, Jiuquan, Jiayuguan and Yumen. There are quite a few county-level cities passing by, so I won't say them one by one.
Another explanation: Yumen city is a prefecture-level city, managed by Jiuquan city; Dunhuang City is a county-level city, which belongs to Jiuquan City.