The state lies mostly on the
Mexican Plateau, with the exception of the eastern part of the state, where the tableland breaks down into the tropical valley of the Tampaon River (which continues flowing northwestward until it becomes the
Pánuco River, which divides San Luis Potosí from the north-eastern state of
Tamaulipas). The surface of the plateau is comparatively level, with some low mountainous wooded ridges. The
Sierra Madre Oriental runs north and south through the state, and separates the Mexican Plateau from the Gulf Coastal Plain to the east. The Sierra Madre Oriental is home to the
Sierra Madre Oriental pine-oak forests. The easternmost portion of the state lies on the Gulf Coastal Plain, and covered by the
Veracruz moist forests. The eastern quarter of the state is known as the
Huasteca potosina, part of
La Huasteca, a geographical and cultural region along the
Gulf of Mexico historically associated with the
Huastec people. The Tampaón river and its tributaries drain the southern and southeastern portion of the state. The northern and central portion of the state, including the capital, lie on an
interior drainage basin which does not drain to the sea. The mean elevation is about , ensuring a mostly temperate climate. The state lies partly within the arid zone of the north, while the southern half receiving more rainfall through the influence of the
Nortes, which deliver significant amounts of rain. The rainfall, however, is uncertain at the western and northern regions, and much of the state does not have major rivers. The soil is fertile and in favorable seasons large crops of wheat, maize, beans and cotton are grown on the uplands. In the low tropical valleys, sugar, coffee, tobacco, peppers and fruit are staple products. Livestock is an important industry and hides, tallow and wool are exported. Fine cabinet and construction woods are also made and exported to a limited extent.
Potosí (in Bolivia) was believed to have enough gold to build a bridge between Potosí and Spain. San Luis Potosí was compared to it upon the discovery of the mines and therefore named after it. At one time San Luis Potosí ranked among the leading
mining provinces of Mexico, but the revolts following independence resulted in a great decline in that industry. The area around
Real de Catorce has some of the richest
silver mines in the country. Other well-known silver mining districts are
Peñón Blanco,
Ramos and
Guadalcázar. The development of Guadalcazar dates from 1620 and its ores yield
gold,
copper,
zinc and
bismuth, as well as silver. In the Ramos district, the Cocinera lode was said to have had a total yield of over $60,000,000 in the first decade of the 20th century.
Municipalities As of 2024, the state of San Luis Potosí is divided into 59
municipalities (), each headed by a
municipal president (mayor). These are similar in function to
counties. As of the 2020 Mexican census, the largest municipalities by population are: •
San Luis Potosí (the state capital) •
Soledad de Graciano Sánchez •
Ciudad Valles •
Villa de Pozos •
Matehuala •
Rioverde •
Tamazunchale Protected natural areas The state has several protected elements included in the federal system of protected areas administered by the
National Commission of Natural Protected Areas (CONANP): •
El Gogorrón National Park (declared in 1936, with , excluded from SINAP); •
El Potosí National Park (declared in 1936, with , excluded from SINAP); •
Sierra del Abra Tanchipa Biosphere Reserve (declared in 1994 with , SINAP 068). •
Sierra de Álvarez Flora and Fauna Protection Area (declared in 1981, with , excluded from SINAP); •
Sierra La Mojonera Flora and Fauna Protection Area (declared in 1981, with , excluded from SINAP); It also has a
Ramsar site declared in 2008,
Arrochas y Manantiales de Tanchachín. In addition, it has 12 other natural areas protected by state competition managed by the
SEGAM (Secretariat of Ecology and Environmental Management): • Natural Monument of "La Hoya de las Huahuas" • Natural Monument of "The
Basement of the Swallows" • La Media Luna Spring State Park • Palma Larga Manantial State Park • Urban Park Paseo de la Presa de San José • Ejido San Juan de Guadalupe Urban Park • Sacred Natural Site "Caves of Wind and Fertility" •
Wirikuta Natural Sacred Site and the Huichol People's Historical Cultural Route • "Real de Guadalcázar" State Reserve • Sierra del Este and Sierra de En Medio State Reserve • Spiny Forest Relic "Adolfo Roque Bautista Forest" • Tancojol State Reserve
Environmental issues Mining In 1996,
Minera San Xavier (MSX), a subsidiary of Canadian company
New Gold, announced plans to start open pit mining at
Cerro San Pedro. There was major opposition to the project, but in 2007, the mine started operating, and was still both active and disputed as of 2016. The mountain is an important site for the
Huichol ceremonial migration,
Peyote hunt, and deer dance. On October 27, 2000, the
United Nations Education, Scientific and Cultural Organization (UNESCO) claimed this site as a protected area for its importance as a cultural route and endemic flora and fauna species. Later on June 9, 2001, it was declared as a National Sacred Site under the State of San Luis Potosí's Natural Protection Act. First Majestic Silver Corp. still decided to purchase mineral rights on November 13, 2009, with 80% of their interest within the protected land. The company's current methods includes
open pit mining and
leaching through
cyanide, using two kilograms of NaCN per tonne of ore. While open pit mining itself removes entire habitats and landscapes, the addition of sodium cyanide (with a mean lethal dose of only 0.2 grams) is potentially lethal. Currently the
Huichol people are trying to find outside groups to help them in the
conservation of their land and culture by protecting this mountain. ==Coat of arms==