Big River is located in the towns of West Greenwich, Exeter, Coventry and East Greenwich, with the major portion within West Greenwich. Interstate Route 95 separates the southern section from the northern segment along several roadways, of which Nooseneck Hill Road (Route 3) and Division Street are major roads. Several gravel roads also exist within the area, most of which are gated to limit vehicle access. Access to the northern segment is limited but occurs along Harkney Hill Road. Access to Big River and Flat River Reservoir is available at Route 3, Zekes Bridge (boat ramp) and the fisherman's access off Weaver Hill Road. U.S.G.S. Topographic quad maps for Crompton and Slocum cover the area.