Global Range: (100-250 square km (about 40-100 square miles)) Because of misidentifications, published records cannot be relied upon to accurately reflect the historic distribution of this species. Museum records indicate that it was distributed throughout a considerable portion of the Interior Basin: Ohio and Sciota rivers (Ohio), Wabash and White rivers (Indiana), Sangamon River (Illinois), Tennessee and Duck rivers (Tennessee), St. Croix and Wisconsin rivers (Wisconsin), Cedar, Iowa, Mississippi, and Racoon rivers (Iowa), Little Fox River (Missouri), and Fall and Neosho rivers (Kansas). Records from the Kiamichi River, Oklahoma, were previously considered uncertain (USFWS, 1997) but recently Hove et al. (2003) confirmed its presence there. All museum vouchers from the Cumberland River (including those of Wilson and Clarck, 1914) are misidentified Quadrula quadrula. Records reported from Alabama (e.g. Ortmann, 1925) are misidentifications of Quadrula quadrula (Williams et al., 2008). There is also a specimen labeled only as "Louisiana", but the identity of the shell and the locality are questionable; Vidrine (1993) lists Quadrula quadrula from Louisiana but includes Quadrula fragosa as a synonym. A single specimen tentatively identified as Q. fragosa recently has been collected from the Ohio River adjacent to Kentucky (Cicerello, Kentucky Nature Preserves Commision, personal communication), but the condition of the shell and any possible population is not known. Hove et al. (2003) have determined that the historical range of this species is greater than once thought; with a historic range of at least 50 linear km in the St. Croix River mostly downstream of the St. Croix Dam (the present range is much less). The only known viable populations are from one section of the lower St. Croix River in Wisconsin/Minnesota and the Ouachita River in Arkansas. Hove et al. (2003) also note the Kiamachi River in Oklahoma.