《明史·志·卷六十七》
从黄甫川的西面到定边营一千二百多里，烽火台城堡迁相呼应，从中截断河套口，里面又挖山填谷，称为夹道，柬面抵达偏头，西面终止于宁、固，这地方风俗强劲凶猛，将帅勇猛士卒尽力，北方人称作橐驼城。
由黄甫川西至定边营千二百余里，墩堡相望，横截套口，内复堑山堙谷，曰夹道，东抵偏头，西终宁、固，风土劲悍，将勇士力，北人呼为橐驼城。
From the west of Huangfuchuan to Dingbianying, for more than one thousand two hundred li, signal towers, forts and castles were interconnected, cutting off the entrance to Hetao, and a mountain valley was dug through, called Jiadao, reaching Piantou on the east and ending at Ning-Gu on the west. The customs of the people of this place were robust and fierce, generals and soldiers were courageous and fought hard. Northerners called the place Tuotuocheng.