The Finke River, starting roughly west of Alice Springs is thought to be the oldest riverbed in the world and although it flows for only a few days a year (in many years it does not flow at all) is home to seven species of fish, two of which are found nowhere else. The waters of the Finke disappear into the sands of the Simpson Desert and are not definitely known to ever make it as far south as Lake Eyre, although the story is told that this happened once early in the 20th century. In extreme events, water from the Finke River flows into the Macumba River, which empties into Lake Eyre, a total distance from headwater streams of around . Major tributaries include Ellery Creek, and the Palmer and Hugh Rivers.