West Region State of Nevada A state located in the western region of the United States of America. Nevada is almost entirely within the Basin and Range Province, and is broken up by many north-south mountain ranges. Most of these ranges have endorheic valleys between them, which belies the image portrayed by the term Great Basin. The southern third of the state, where the Las Vegas area is situated, is within the Mojave Desert. LanguaL curation note: US FDA 1995 Code: US32 nevada West Region State of Nevada A state located in the western region of the United States of America. Nevada is almost entirely within the Basin and Range Province, and is broken up by many north-south mountain ranges. Most of these ranges have endorheic valleys between them, which belies the image portrayed by the term Great Basin. The southern third of the state, where the Las Vegas area is situated, is within the Mojave Desert. LanguaL curation note: US FDA 1995 Code: US32 nevada