Across the entire 1,142-square-mile watershed located in south Central Ohio, 70 percent of the sites Ohio EPA studied in 2006 for biological health and recreation use fully met aquatic life use goals; however, nearly half of the 117-mile-long river‚s mainstem is only partially meeting goals for aquatic life and only 40 percent met recreation use goals due to bacterial impairment. The watershed includes tributaries in parts of Fayette, Highland, Ross, Clark, Clinton, Madison, Pike, Pickaway and Greene counties.