Together with Fray Isidro de Espinosa, they explored the territory from the modern-day city of San Antonio to the Colorado River.

[2] In 1716, Fray Antonio wrote to the Viceroy of New Spain, Baltasar de Zúñiga y Guzmán, telling him their hopes and plans for the future mission, and urged him to send families of settlers to found a town.

[4] In the same letter he stressed that it was necessary that some of these families be skilled in the useful arts and industries, "to teach the Indians all that should be required to be useful and capable citizens."

The perseverance of Fray Antonio was answered, as the Viceroyalty gave formal approval for the mission in late 1716, assigning responsibility for its establishment to Martín de Alarcón, the governor of Coahuila y Tejas.

[5] He remained at the site of the mission for some time, organizing everything with the Indians, and they constructed a straw structure with branches and mud near the head of the San Antonio River.

[4] It was designed to protect the system of missions and civilian settlements in central Texas and to ensure Spanish claims in the region against possible encroachment from other European powers.

As the bulwark of Spanish Texas, located in the center of several operating missions, Bejar escaped the anxieties of other settlements.

The operational complex was completed with the construction of the first canal in Texas (Acequia Madre de Valero),[6] 6 miles long, built to irrigate 400 hectares and supply of the inhabitants of the new facilities.

Acequia Madre de Valero ran from the area currently known as Brackenridge Park southward to what is now Hemisfair Plaza and South Alamo Street.