The state surface is part of the provinces of Sierra Madre Oriental, Great Plains of North America and Northern Gulf Coastal Plain. Due to the action of the marine currents at the edge of the sea, a series of beaches have been formed that have separated and formed bodies of water such as the Laguna Madre.
In the west and on the international border there is an extension of hills, interrupted in the central part by the Chiquita mountain range.
There are mountain ranges in the southwest, predominantly formed by sedimentary rocks (formed on beaches, rivers and oceans and where sand and mud accumulates), some intrusive igneous rocks (formed below the Earth's surface) and metamorphic rocks (which have undergone changes due to pressure and high temperatures). In these elevations, the highest is represented by the Peña Nevada hill with 3 510 meters above sea level.
