Occurrences CommentsIn Minnesota, it is in the Red River of the North, Minnesota, and St. Croix drainages, and Mississippi River drainage below St. Anthony Falls; rare in the Rainy River drainage and SE streams (Sietman, 2003; Graf, 1997; Cvancara, 1970); also Lake of the Woods (Hove et al., 1997). In Illinois, it is sporadic in the northern half, in half the drainages it once occupied (Cummings and Mayer, 1997; Schanzle and Cummings, 1991) but healthy in Vermillion (Wabash drainage) and Kankakee systems (Schanzle et al., 2004); Fox and other upper Illinois basins with some decline (esp. in Wisconsin) (Sietman et al., 2001; Schanzle et al., 2004). Indiana distribution: Tippecanoe (Cummings and Berlocher, 1990), East Fork White (Harmon, 1992), Muscatatuck (Harmon, 1989), St. Joseph and Maumee (Pryor, 2005). It is widespread but sporadic in glaciated Ohio (Watters, 1992; 1995; Lyons et al., 2007; Grabarciewicz, 2008; Watters et al., 2009). In West Virginia, it occurs in the Mud (Guyandotte drainage) (Schmidt and Zeto, 1986) and Upper Kanawha (Morris and Taylor, 1992); and upper Clinch River, Virginia (Jones et al., 2001) incl. Copper Creek (Hanlon et al., 2009). It is in the Poteau (Vaughn and Spooner, 2004), lower Arkansas (Frog Bayou) (Gordon, 1985), Ouachita (Posey et al., 1996), and White (Gordon, 1982; Christian, 1995) River drainages, Arkansas. In Kansas, it is in the Neosho and Spring (Branson, 1966) River basins with relic shells in the Marais des Cygnes and Pottawatomie Creek (Marais des Cygnes River basin), and Fall, Elk, Big Caney, and South Fork of the Cottonwood River (Neosho River basin) (Couch, 1997). In Vermont, it is in Lake Champlain tributaries (Fichtel and Smith, 1995) in Lamoille, Winooski, Poultney Rivers, Otter and Lewis Creeks, and Missisquoi River (shells) (Kart et al., 2005). In Wisconsin, it is common and widespread except the SW section of the state (Mathiak, 1979). In Virginia, it was recently in the upper South Fork Holston (Stansbery and Clench, 1978), Powell and Clinch Rivers (Ahlstedt and Tuverville, 1997), and upper North Fork Holston River (Jones and Neves, 2007) where it is rare. In Tennessee, it is most common in east and middle Tennessee from unimpounded upper Powell and Clinch Rivers and other tributaries of the upper Tennessee system, S and W to the Elk, Duck, Stones, Big South Fork Cumberland, and Harpeth Rivers (Parmalee and Bogan, 1998). In Alabama, it is uncommon and limited to the Tennessee River system extant only in the Paint Rock and Elk Rivers and a short reach of Bear Creek in Colbert Co. (Ahlstedt, 1996; Mirarchi, 2004; Williams et al., 2008). It has been collected in Kentucky in the South Fork Kentucky (Evans, 2008), Middle Green (Gordon, 1991) and Barren Rivers (Cochran and Layzer, 1993), but is generally distributed in the Tennessee River eastward (Cicerello and Schuster, 2003) and Red River (Clark, 1988). Athearn (1992) lists a range extension into Georgia in South Chickamauga Creek in Catoosa Co. It occurs in the Lake Michigan and St. Clair drainage (Badra and Goforth, 2003), Michigan (Strayer, 1980; Trdan and Hoeh, 1993) and parts of the upper peninsula (Goodrich and Van der Schalie, 1939) and Kalamazoo River (Mulcrone and Mehlne, 2001). It is rare in Oklahoma in: Neosho, Little (Vaughn and Taylor, 1999), Glover, and Mountain Fork (Spooner and Vaughn, 2007) Rivers, and eastern tributaries of the Arkansas River (possibly historic) (Branson, 1983; Vaughn, 2000). In Canada, it is abundant in Ontario (particularly southern), the core of its Canada range, and less abundant with decline in Manitoba (Red and Winnipeg Rivers- Watson, 2000) and Quebec; likely extirpated from the St. Lawrence River (Metcalfe-Smith and Cudmore-Vokey, 2004). Clarke (1981) lists Canadian distribution as Hudson Bay drainage in the Red and Winnipeg River systems; Great Lakes-St. Lawrence system from southern Lake Huron and tributaries to the Ottawa River and Lake Champlain; and entire Ohio-Mississippi River system.