The FWGNA Project is a long term, collaborative effort to inventory and monograph the entire freshwater gastropod fauna of the continental United States and Canada. In Volume 1 of this series, we documented the distribution and abundance of 69 species inhabiting Atlantic drainages from Georgia to the New York line. Here in Volume 5 we expand our survey into the rivers, lakes, ponds, and streams of the Ohio drainage, together with its primary tributaries...