Occurrences CommentsIn Minnesota, it is widespread and abundant in the Mississippi River below St. Anthony Falls (recently expanded above the falls), and common in the lower St. Croix River; uncommon in the Minnesota River (Sietman, 2003). In Illinois, it is distributed and common in the larger rivers (Cummings and Mayer, 1997; Schanzle and Cummings, 1991); and much of Indiana including Wabash (Fisher, 2006). In Ohio, it is sporadic in southern rivers (Muskingum, Ohio Brush Creek) (Watters, 1992; 1995; Hoggarth et al., 2007; Watters et al., 2009), but may be extirpated from Lake Erie drainages. Recently the James (Perkins and Backlund, 2003) and Big Sioux River, South Dakota (Backlund, 2000). Oklahoma: Blue, Muddy Boggy, Kiamichi, Little (Vaughn and Taylor, 1999), Verdigris (Boeckman and Bidwell, 2008), Neosho, North Fork Canadian, Poteau Rivers; large creeks of the Arkansas drainage (not Chickaskia drainage); Neosho, Poteau, Lake Texoma, Big Caney (Washington Co.), Salt (Osage Co.); Washita, Blue, Kiamichi, Little and Glover Rivers and Pennington Creek; Tenkiller Ferry Reservoir (Illinois River) (Branson, 1984; Vaughn, 2000). In Kansas, it is in the Marais des Cygnes, Fall, Elk, Verdigris, Cottonwood, and Neosho Rivers but is likely extirpated from the Walnut and Spring Rivers (Couch, 1997). In Texas, it occurs from the Trinity drainage basin into systems north and east (Howells et al., 1996) incl. Village Creek drainage of Hardin, Tyler, and Polk Cos. in SE Texas in 2001-2002 (Bordelon and Harrel, 2004). It is threatened in Ohio and was recently found in Ohio Brush Creek (Matter et al., 2006). Although formerly thought to be extirpated in Pennsylvania (Bogan, 1993), it may still occur in the Upper Ohio basin (PA NHP, pers. comm., 2007) where it was widespread incl. Lower Monongahela basin (Ortmann, 1919). In West Virginia, it occurs in the Upper Ohio/Kanawha (Zeto et al., 1987). In Mississippi, it occurs in the Mississippi River North, Big Black, Yazoo, Tennessee, Pearl, and Tombigbee drainages (Jones et al., 2005). In Louisiana, it is widespread in the Pearl, Tqngipahoa, and Amite Rivers (Brown and Banks, 2001); upper Mississippi, Tensas, Boeuf, Bayou Bartholomew, Ouachita, Black, Little, Caddo, Bayou Pierre, Bayou Teche, Calcasieu, and Sabine and Neches Rivers (Vidrine, 1993). It occurs in Arkansas in the Ouachita (Posey et al., 1996; Posey, 1997), Poteau (Vaughn and Spooner, 2004), St. Francis (Ahlstedt and Jenkinson, 1991), Cache and White Rivers (Christian, 1995; Christian et al., 2005; Gordon, 1982; Gordon et al., 1994); and lower Arkansas (Gordon, 1985). In Tennessee, it is throughout the Cumberland and Tennessee Rivers and major tributaries and is relict in the Hatchie River in west Tennessee. It has expanded its range upstream in the Cumberland and Tennessee Rivers (in reservoirs) (Parmalee and Bogan, 1998). McGregor and Garner (2004) listed it in the Bear Creek drainage in Alabama/Mississippi. In Alabama, it is common throughout the Tennessee River system and Mobile basin (Ahlstedt, 1996; Mirarchi, 2004; Williams et al., 2008; McGregor et al., 1999). It is in Kentucky in the Middle Green and Barren Rivers (Cochran and Layzer, 1993), but is distributed to occasional nearly statewide (Cicerello and Schuster, 2003). In the Coosa River basin in Georgia, it occurs in the Coosa, Etowah, Oostanaula, and Conasauga River drainages (Williams and Hughes, 2001). This species was recently collected from the Black Warrior River in Tuscaloosa and Greene/Hale Cos. and upper Tombigbee River in Sumter and Greene Cos., Alabama (Williams et al., 1992). In Wisconsin, it is known from the Wisconsin and Mississippi Rivers (Mathiak, 1979). It is in Michigan in St. Clair drainage (Badra and Goforth, 2003). In Canada, it is rare with a few specimens in recent years in the Sydenham River, Ontario (Metcalfe-Smith et al., 2003), and historically in the lower Thames and Grand Rivers and western Lake Erie, all Ontario (Metcalfe-Smith and Cudmore-Vokey, 2004).