Valles Caldera Valles Caldera dates back to the prehistoric times: spear points dating to 11,000 years ago have been discovered. Several Native American tribes frequented the caldera, often seasonally for hunting and for obsidian, used for spear and arrow points. Obsidian from the caldera was traded by tribes across much of the Southwest. Eventually, Spanish and later Mexican settlers as well as the Navajo and other tribes came to the caldera seasonally for grazing with periodic clashes and raids. Later as the United States acquired New Mexico as part of the Treaty of Guadalupe Hidalgo in 1848, the caldera became the backdrop
Delia Guerrero Coronado degree in Administration of Nursing Services. Her involvement in PRI politics began in earnest in 2003, when she was elected as a town councilor in Ciudad Valles for a three-year term. She also coordinated the National Fair of the Huasteca Potosina, held in Ciudad Valles, from 2004 to 2005. After a time in which she worked in various PRI positions and was a municipal-level coordinator in the early stages of the PRI's San Luis Potosí gubernatorial campaign, Guerrero ran for and won a seat in the federal Chamber of Deputies from the Fourth Federal Electoral District of San Luis Potosí,