Schemes including Crotalus oreganus helleri

• The Reptile Database (Crotalus_oreganus_helleri) Crotalus oreganus helleri
• NatureServe Explorer: An online encyclopedia of life. Version 7.1 (ELEMENT_GLOBAL.2.102481) Crotalus oreganus helleri
• CONABIO (25984REPTIB501112) Crotalus oreganus helleri
• GBIF (6157440) Crotalus oreganus helleri