Big Muddy River Here the outline of the Wisconsinan Era lake bed is evident in what were the northern reaches of the ancient lake, where the lake bed was only a few hundred feet wide. The steep Illinoian hills are suddenly truncated where they meet the flat bottom of the Wisconsinan Era lake bed. Here the tributaries of the Big Muddy are tiny, intermittent streams, meandering though these narrow valleys at the headwaters. The Big Muddy basin contains a significant portion of the planet's coal reserves. Most of this is hidden under its deep mud. At a few places the river has eroded
Olifants River (Southern Cape) the east and flows westwards between the Swartberg and Kammanassie mountains to its confluence with the Gamka River. The southern slopes of the Swartberg Mountains are drained by the perennial Groot River, Kango River, Grobbelaars River, Wynands River, Kansa River and Vlei River tributaries, which flow into the Olifants River. The Kammanassie River rises in the Outeniqua and Kammanassie mountains near Uniondale and joins the Olifants River upstream of Oudtshoorn. Olifants River (Southern Cape) Olifants River () is a river in the Klein Karoo area of the Western Cape, South Africa. It has its origins in the Traka and Kalkwal