Yu Huang Gu Dao (King Yu's Course)
The following map is the only historical map I know which takes the trouble of researching into, and presenting, the position of the Yellow River on the plain during the historical period for which the map is suppose to illustrate. The most northerly flowing channel, called He Shui in ancient texts, is now referred to as the Yu Huang Gu Dao. The channel which corresponds more or less to the modern course is called Ji Shui, as shown in this map.
A look at the topographic map of the region (shown below), you'll see the Yu Huang Gu Dao followed a course very close to the Taihangshan mountain range. (A more detailed
illustration on a 100K file may be selected.)
Sources: (top map) Guo Moruo (chief ed.), Atlas for the Notes on a Historyof China, Cartographic Publishing House, Shanghai, 1979; (bottom map) Atlas of the People's Republic of China, Cartographic Pub House, Beijing, 1974.