Clarion River possibly is one of the worst streams in the state. In the region of its headwaters, in Elk County, it is not mine water, but the refuse of various establishments, such as wood-pulp mills, tanneries, chemical factories (Elk Creek), which renders the water unfit for life, and finally Toby Creek, emptying into it in the southwestern portion of Elk County, adds its share in the form of mine water. The water of Clarion River, in this region, is black like ink, and retains its peculiar color all the way down to where it empties into the Allegheny (at Foxburg); here the deep blackish brown color of the Clarion River water contrasts sharply with the bluish green water of the Allegheny River.