sentences:  The higher mountain areas to the west often have tall peaks in capricious forms with steep slopes and eight fast running rivers.Highways in the region tend to be small and winding, especially in the higher elevations in San Luis Potosí and Hidalgo.Most of these river eventually empty into either the Pánuco or the Cazones River with the zone belonging to the Pánuco, Tuxpan and Cazones River basins, all of which empty into the Gulf of Mexico.