This is a detailed map of the ancient Yellow River delta. The Yu Huang Gu Dao is shown by the purple-color line running along the top-most part of the delta. Called Yu He Gu Dao 禹河故道 in this map, it follows a fault line parallel to the Taihangshan mountain range 太行山 (in yellow terrain color). Geological evidences indicate that it was the main course taken by Yellow River from 2278 BC to 602 BC. The red line just below it denotes the Xi Han Gu Dao (Course at Western Han Dynasty 西汉故道) adopted by the Yellow River from 602 BC to 11 AD. The land on the east shown by yellow terrain color belongs to the highland surrounding the Taishan mountain.
The modern channel is shown in white between dark lines (which indicate locations of dikes). The short red arrows denote positions of breaches of the dikes along its course. During the Ming and Qing dynasties the Yellow River took a course south of the Taishan mountain, into the Huai River valley. It is shown in blue here, and is called the Ming-Qing Gu Dao (1368-1855) 明清故道.
When the Yellow River adopted the Yu Huang Gu Dao, this ancient delta was relatively free of floods, which allowed the Xia 夏 and Shang 商 dynasties to prosper here and achieve an era of high civilization.