Known from the Columbia River drainage in Washington, Oregon and Idaho, south in Klamath and upper Pit River (Sacramento River drainage) and interior drainages of Nevada and California to Mohave River in south California. Locally abundant but declining in some areas because of habitat degradation and introduced species (Ref. 5723, 86798).

Status of threat of the following subspecies: 1). Gila bicolor euchila: endangered; status declined since 1989. Criteria: 1,4,5; 2). Gila bicolor eurysoma: endangered; status declined since 1989. Criteria: 1,5; 3).

Gila bicolor isolata: endangered; status improved since 1989. Criteria: 1,4,5; 4). Gila bicolor mohavensis: endangered; status same as 1989. Criteria: 1,4,5; 5). Gila bicolor newarkensis: threatened; status declined since 1989. Criteria: 1,5; 6). Gila bicolor oregonensis: threatened; status declined since 1989. Criteria: 5; 7). Gila bicolor snyderi: endangered; status same as 1989. Criteria: 1,4,5; 8). Gila bicolor thalassina: threatened. Criteria: 1,4, 5; 9). Gila bicolor vaccaceps: endangered; status declined since 1989. Criteria: 1,5 (http://fisc.er.usgs.gov/afs/) (Ref. 81264).