South Fork – Cheyenne River

Once a Great River The Cheyenne is, after the Yellowstone, the largest tributary of the Upper Missouri. It once, before the Ice Age established the Missouri where it is now, flowed on east and turned North to Hudson’s Bay. That old valley, full of glacial drift is now the source of underground water for Eastern South Dakota.

The South Fork here, has a drainage area as large as the entire states of Massachusetts, Rhode Island and Connecticut combined. Old Spanish maps called it the Chyanne; Trudeau, 1794 called it the Chaquiennes; Evans, 1796, the Shayenne; Perrin du Lac, 1802, the Chaquyene. Unquestionable named for the Cheyenne Indians who roamed North of it when white men came, Lewis & Clark called it the Chien (French) or Dog River by what appears to be a mistake induced by the similarity of sounds.

The Fur Traders floated their pelts to Ft. Pierre on it in huge skin canoes. In 1830 over 5,500 buffalo robes passed this point in this way, from the Oglalla Post at the mouth of Rapid Creek above, in March and April. Early stockmen all testify that the Cheyenne, wherever encountered, swam their horses.

Great Reservoirs on both forks, thousands of stock dams, irrigation withdrawal so depleted it now that only a flash flood can restore the torrents that once poured down it. Time marches on.