The plains range is from the Mexican border with the United States to Cape Corrientes, about range of about half the western coast of Mexico, and includes Baja California.One physical feature of this region is that it has mountains bordering the ocean. There are more potentially active volcanoes in this region than in any other region in the Lower 48.
The Baja California Peninsula spans from the US-Mexico border to Cape Corrientes, covering roughly half of Mexico's western coastline. A notable characteristic of this area is its rugged terrain where mountains meet the ocean. This region has a higher concentration of active volcanoes compared to any other part of the contiguous United States.