Clear tributaries of the Conemaugh are found in the valley between Chestnut Ridge and Laurel Hill: Tub Mill Run, for instance, near New Florence, is very good (trout stream). As has been said, Stony Creek, in Somerset County, is polluted. Of its tributaries, at least one is in good condition: Quemahoning Creek; others have not been investigated, but probably there are more clear streams, chiefly among the headwaters coming down from Laurel Hill and Allegheny Front.