Little Don River

The Little Don River also known as the Porter, is a tributary of the River Don in South Yorkshire, England. Arising on the Langsett Moors in the northern Peak District, the Little Don River feeds the Langsett and Underbank Reservoirs. It runs through the town of Stocksbridge before joining the River Don. A 2.7-acre (1.1-hectare) section of the river has been designated as a site of special scientific interest since 1977. The site is of considerable importance as it is a proposed reference example for various subdivisions of the Carboniferous. It is one of 35 sites of special scientific interest in South Yorkshire.