The southernmost forests transition to the Trans-Mexican Volcanic Belt pine-oak forests in Puebla state, near the southern end of the Sierra Madre Oriental. The forests extend almost continuously along the range through the states of Veracruz, Hidalgo, Queretaro, Guanajuato, San Luis Potosí, Tamaulipas, and Nuevo Leon. North of Monterrey, the forests become discontinuous, extending as a series of sky islands through the states of Nuevo Leon and Coahuila, and on into the Chisos and Davis mountains of the Big Bend region of western Texas. Other sky islands can be found on the higher peaks of the mountain ranges rising from the Mexican Plateau to the west.