The historical range of the upland combshell included portions of the Black Warrior, Cahaba, and Coosa Rivers of the Mobile River Basin and some of their tributaries in Alabama, Georgia, and Tennessee. The last known collection of the upland combshell was 1986 from the Conasauga River, Georgia (Shelton-Nix 2017). When listed, the species was believed to be restricted to the Conasauga River in Georgia, and possibly portions of the upper Black Warrior and Cahaba River drainages. Surveys of Coosa River tributaries have since been conducted by Service biologists, as well as Bogan and Pierson (1993a), Dinkins (2008), Dinkins and Hughes (2011), Evans (2001), Gangloff (2003, 2005), Golder Associates 2008, Johnson (2006), Johnson and Evans (2000), Johnson et al. 2005, Pierson (1993), Krause et al. (2012), McGregor and Garner (2004), Moran (2011 and 2017), Williams and Hughes (1998), and others. Surveys of the Cahaba River have been conducted by Service biologists, Bogan and Pierson (l993b), Freeman 2011, McGregor et al. (2000), McGregor and Garner (2004), Shepard et al. (1994), Johnson et al. (2006), and others. Surveys in the upper Black Warrior drainage have been done by Service biologists, Sheppard et al. (1998), Warren and Haag (1994), Haag and Warren (2003), Garner et al. (2014), McGregor and Wynn (2008), McGregor et al. (2013), and others. All surveys have failed to locate any evidence of the persistence of the upland combshell, and some authors believe the species to be extinct (Evans 2001, Gangloff 2003, Gangloff and Feminella (2007), Williams et al. (2008), and Shelton-Nix (2017). Considered extinct by many experts