Cascade-Sierra province
The Cascade-Sierra province is a physiographic region of mountains in the western United States, east and adjacent to Pacific Border province and west and adjacent to the Basin and Range Province (in the south) and Columbia Plateau Province (in the north). == About the region == The Cascade-Sierra province stretches approximately 1,000 mi (1,600 km) from the high desert region of the Mojave Desert in Southern California to just north of the border between British Columbia and the state of Washington.