Where is Dingxiang in Han Dynasty now?

Dingxiang County was included in Yunzhong County in the Western Han Dynasty, where it ruled successfully (so it was ruled in Tuchengzi and Helinger in the southwest of Inner Mongolia Autonomous Region). -"Shanxi Historical Geography Directory"

By the end of the Western Han Dynasty, Shuofang County 10, Wuyuan County 16, Yunzhong County 1 1, Dingxiang County 12. -History of Chinese Geography

In the Western Han Dynasty, a "white canal" was built in Wujin County, Dingxiang County. Baiqu originated from Gukou (also known as Xuankou and Hongkou, now northeast of Shaanxi Liquan)-Notes on Water Classics and Rivers.

During the period of Emperor Wu of the Han Dynasty, the northern border counties were divided and merged, and new counties such as Shuofang, Xihe, Anding, Tianshui, Jincheng, Jiuquan, Wuwei, Zhangye, Dunhuang and Dingxiang were added 10, and the original county 12 was added, making a total of 22 counties, which were distributed along the Great Wall and were called "Northern 22 Counties" in history.

It can be roughly delineated that Dingxiang County is now in the south of Inner Mongolia, the north of Shaanxi, the south of the Han Great Wall and the northern end of Hetao.