The Little Miami IBA follows the riparian corridor of the Little Miami River 105 miles from its source in Clark County to its mouth at the Ohio River. The river has State and Federal Scenic River designations, flowing through numerous scenic gorges, though most of its length is agricultural. Its course encompasses portions of Clifton Gorge State Nature Preserve, John Bryan State Park, Glen Helen Ecology Institute, Spring Valley Wildlife Area, Fort Ancient State Memorial, and Camp Dennison. Spring Valley Wildlife Area was once a commercial fur farm, and now supports one of the largest high-quality emergent marsh and scrub-shrub wetland complexes in southwest Ohio.
The river corridor is significant for distribution patterns up the river (illustrated from the first Ohio Breeding Bird Atlas) of Blue-winged Warbler, Northern Parula, Prairie Warbler, Hooded Warbler, Yellow-throated Warbler, Louisiana Waterthrush, and Yellow-throated Vireo.
Over 230 species have been recorded at Spring Valley WA and the extensive wetlands attract rare migrant and breeding birds. The uniqueness of the site is evident by the regularity of rare and accidental birds. These include American Bitterns, Least Bitterns, Soras, Virginia Rails, Common Moorhens, and Northern Waterthrushes. In fact, there are at least three records of Purple Gallinule, plus records of White Ibis, Little Blue Heron, Yellow-crowned Night-Heron, King Rail, Yellow Rail, Black Rail, Brewer's Blackbird, and Nelson's Sharp-tailed Sparrow. Spring Valley has been an Osprey re-introduction site.
Camp Dennison has American Coot in typical numbers of 1,000 avg. daily (2,200, 30 Oct 2006, Ohio Cardinal).
Active gravel mining operation northwest of the site of Spring Valley Wildlife Area poses potential threat to its hydrology. Bush honeysuckle has seriously degraded the upland areas surrounding much of the public land along the river. Housing development in some counties along the river is rapidly increasing and may pose problems for surface water runoff. The rare massasauga rattlesnake is found at Spring Valley Wildlife Area.