only slightly above 6.0. However, it is usually between 6.5 and 7.5. The creek does not experience severe episodic acidification. The discharge of Coles Creek is usually less than two cubic meters per second. However, it is sometimes between two and four cubic meters per second and in isolated instances can be as high as seven to eight cubic meters per second. In the creek, the pH tends to be lower when the discharge is higher. The concentration of dissolved aluminum in Coles Creek is usually between 0 and 20 micrograms per liter. In some cases, it is between 20 and 40 micrograms per liter and in one case the concentration has been measured at approximately 70 micrograms per liter. The maximum concentration of dissolved aluminum in the creek is higher than in any other location in the upper Fishing Creek watershed except for East Branch Fishing Cree and West Branch Fishing Creek. Geology Almost all of the watershed of Coles Creek lies over the Catskill Formation. This rock formation consists of sandstone and siltstone and comes from the Devonian period. The headwaters of the creek lie over the Huntley Mountain Formation. The Huntley Mountain Formation consists of sandstone and siltstone and comes from the Mississippian and Devonian periods. There is a moraine at the confluence of Coles Creek with Fishing Creek. This causes there to be cone-shaped hills in the area. Watershed The watershed of Coles Creek has an area of 11.6 square miles. The drainage density of the watershed is 1.3 per mile. There are of streams in the watershed. Most of the area along the creek is forested or residential. There are also scattered patches of agricultural land in the watershed. Additionally, there is a small patch of industrial land in the lower reaches of the creek. It occupies less than 0.09 square miles. Major roads in the watershed of Coles Creek include Pennsylvania Route 118 and Pennsylvania Route 487. A community known as Coles Creek is located at the confluence of the creek with Fishing Creek. History Coles Creek was likely named between 1800 and 1810 after Ezekiel Cole, a mill owner in the area. A fish habitat made of log cross vanes was installed in the headwaters of Coles Creek in 2012. Biology The biodiversity level of Coles Creek is similar to parts of the upper reaches of the main stem of Fishing Creek. In