In 1986 and 1987 the Illinois Environmental Protection Agency and Illinois Department of Conservation conducted a cooperative survey of 14 Shawnee National Forest region streams in Southern Illinois. Monitoring included collection of aquatic macroinvertebrates, water quality, sediment chemistry, stream habitat, and fish population samples. Biological, chemical, and physical data collected during the Shawnee study revealed an unusual assemblage of high quality streams characterized by excellent biotic integrity and water quality, and exceptional physical and aesthetic attributes. Outstanding streams in the Shawnee National Forest include Big, Lusk, and Big Grand Pierre Creeks in the Ohio River watershed and upper Clear and Miller Creeks in the Mississippi River watershed. Streams exhibiting lowest quality included lower Bay Creek, Bay Creek Ditch, and Cedar Creek in the Ohio drainage, and the lower Clear Creek continuum near the Shawnee's western edge. High quality streams were generally located in the Shawnee Hills or Ozark Natural Divisions; low quality streams were generally located in agricultural bottomlands.