This is due to the mountains’ blocking of moisture coming in from the Gulf of Mexico, which generally makes the east side fairly moist and the west semiarid scrub brush.

The limestone has been affected by erosion to form the Huasteca Karst, and the area contains a large number of caverns, and pit caves (sótanos), some of which extend for hundreds of meters in depth.

Among its mountains are the peaks associated with the Sierra Alta de Hidalgo, the pine forests of Zamoarano, the Extoraz Canyon and the slopes of the Huazmazonta, the inter-mountain valleys where the five missions are found and the rolling hills leading into La Huasteca.

[3][10] Species in danger of extinction include the jaguar, puma, the black bear, the green parrot, the Veracruz partridge, and the Humboldt butterfly, mostly due to human activities.

[9] The reserve begins in the dry semi desert areas in the center of Querétaro and as one moves north and higher into the mountain peaks of Pinal de Amoles at around 3,100 metres (10,200 ft), the scenery changes to temperate forest of conifers.

The elevation is lower north into Jalpan and the climate is warmer and wetter before moving into the rolling hills of the La Huasteca in San Luis Potosí and Hidalgo.

[23] Elevations in the reserve range from 350 to 3,100 meters above sea level, with rugged mountains, canyons, lush valley and “sótanos” or pit caves carved out from the limestone of the Huasteca Karst.

[18][21] Humidity is primarily from the Gulf of Mexico, which makes the northeast of the region green, but the southwest, blocked from the moisture by the high mountains, is dominated by arid scrub brush.

[24] This combination of varying elevation and moisture patterns creates the regions primary biological characteristic, which is a large number of ecosystems in a relatively small area.

In this state, protected area covers 236,882 hectares which is the entire municipality of Xichú, 70% of Victoria, 65% of Atarjea, about a quarter of San Luis de la Paz and a small portion of Santa Catarina.

It lowest point is a canyon called Paso de Hormigas in Xichú at 650 meters above sea level with a very warm climate suitable for tropical fruit.

Recently, the federal government along with the United Nations, began a program to pay private land owners for "environmental services" of between 18 and 27 US dollars for each hectare they conserve each year.

Agriculture is limited to corn grown during the rainy season but yields are poor due to the lack of flat lands and fertile soil.

While indigenous people make up a very small percentage of the population of the region, the Huasteca culture has had a strong impact since the pre Hispanic period.

[30] Huapango is the dominant native musical and dance style in the Sierra Gorda, with festivals dedicated to it in Xichú, Pinal de Amoles, San Joaquín, where Huasteca influence is strongest.

[21] There is an annual cycling event called "Escalera del Infierno" (Hell's Ladder) which extends over the Sierra Gorda in Querétaro in March.

Most settlements are found near springs, ponds and small lakes as they were the most readily usable sources of water, instead of the rivers which ran deep inside narrow canyons.

The Serrana Culture is found around the archeological sites of Las Ranas and Toluquilla, which dominated most of the trade routes, and had the greatest population during the Classic Period (200-900CE).

[11][40][41] The Spanish entered the heart of the Sierra Gorda early, with Nuño de Guzmán conquering the Oxitipa dominion, which encompassed Jalpan, Xilitla, Tancoyol and Tilaco in 1527.

[11] Systematic evangelization of the Querétaro area would not be attempted until the 17th century, when Augustinians in the east and Franciscans in the west began building missions in 1670 and 1680s, under the military protection of Captain Jerónimo de Labra.

[42] In 1740, the colonial government in Mexico City decided to extinguish indigenous resistance the Sierra Gorda, and send an expedition headed by José de Escandón to accomplish this.

The uprising spread to nearly all parts of the Sierra Gorda region from Guanajuato to San Luis Potosí to Veracruz, with the most activity in Santa María del Río, Xichú and Rioverde between 1847 and 1849.

[9][45] This complex is situated in the center of the modern town in front of the main plaza and formed by an atrium, cloister, pilgrim portal and church, with a chapel annex on the left side.

[4] The main features of the ornate portal on the facade are Our Lady of the Pillar and the Virgin of Guadalupe, both with Mesoamerican connections, as well as a double headed eagle, meant to symbolize the blending of the two cultures.

[4] At the end of the Preclassic, most of the Sierra Gorda was populated by agricultural villages established by people who migrated here from the Mexican Plateau and Gulf of Mexico coast, mostly from the latter.

Most settlements are found near springs, ponds and small lakes as they were the most readily usable sources of water, instead of the rivers which ran deep inside narrow canyons.

[10] The mining of cinnabar required coordinated and hierarchical labor practices for the various tasks involved, which would lead to the development of the cities of Las Ranas and Toluquilla.

The discovery of these two cities generated academic interest, but they were not further explored until 1931, when archeologist Eduardo Noguera and architect Emilio Cuevas went to evaluate the sites for the Direction of Pre Hispanic Monuments.

[48] The mummy of a girl was found in a cave near the community of Altamira in the municipality of Cadereyta de Montes which shows evidence of agricultural settlement in an area that today does not support it.

[4] In 2009, INAH and other institutions carried out research at Toluquilla on thirty skeletons from the pre Hispanic era in order to determine the importance of mining in the south of the Sierra Gorda.