《水经注·卷十一》
汉章帝章和二年巡视北岳，以为曲逆这地名不好，于是就因水改名为蒲阴。
汉章帝章和二年，行巡北岳，以曲逆名不善，因山水之名，改曰蒲阴焉。
In the second year of Emperor Zhang of the Han Dynasty, he visited Beiyue and thought that the name of Quyu was not good, so he changed it to Puyin because of the water.