《汉书·志·地理志下》
羌道县，羌水流出塞外，向南到阴平县流入白水，经过三个郡，行程六百里。
羌道，羌水出塞外，南至阴平入白水，过郡三，行六百里。
Qiangdao County, Qiangshui River flows outside the border, enters Baishui in Yinping County to the south, and flows through three counties, with a distance of 600 li.