Cocopás, Sierra de los (ko-ko-PAHS), precipitous range in N Lower California, NW Mexico, 10 mi/16 km SW of Mexicali; extends c.40 mi/64 km SE from U.S. border, E of Laguna Salada and Hardy R., S of Imperial Valley; rises to 3,475 ft/1,059 m. Sulphur deposits. Sometimes spelled Cucopas or Cucapahs.