The Eyre Mountains borders the southern flanks of Lake Wakatipu and lies between the distinctive wet granite mountains of Fiordland and the classic drier schist landscape of Central Otago. Being located in this geological and climatic transition zone has resulted in some rare and localized flora and fauna as well as a rugged jumble of ridges, high peaks and long narrow river valleys. The Oreti River originates from the western catchments and is reputed to be one of the best trophy brown trout rivers in the world.