El Orcoquisac, a Spanish outpost (1765–71), was located north of the site of present Wallisville and east of the Trinity River in what is now northern Chambers County. The settlement consisted of San Augustín de Ahumada Presidio and Nuestra Señora de la Luz Mission. The presence of Indians, primarily the Bidais and Orcoquizas, lured French traders into the surrounding region as early as the 1720s. Persistent rumors of Frenchmen operating out of the lower Trinity reached the ears of Governor Jacinto de Barrios y Jáuregui at Los Adaes. Alarmed over the French presence and the threat it posed to his own illegal trade monopoly with the Indians, the governor in 1754 dispatched Lt. Marcos Ruiz and a force of twenty-five soldiers to arrest the Frenchmen reputed to be operating near the mouth of the Trinity. Ruiz, after gaining the support of the Bidai and Orcoquiza villages nearby, arrested Joseph Blancpain of Natchitoches, four associates, and two Blacks on October 10, 1754. Blancpain's log trading post was dismantled, and the lumber was given to the Orcoquizas. The prisoners were marched to Mexico City, where Blancpain died on February 6, 1756. After considerable discussion, Barrios decided to establish an outpost on the site of the French trading post. Ruiz marched to the Trinity with thirty-one men, 151 horses, guns, swords, saddles, supplies, and other military equipment in May 1756. He took possession of the site eleven days later. The presidio was named San Augustín de Ahumada in honor of the viceroy. Temporary structures were completed by July 12, 1756.
Two missionaries from the College of Nuestra Señora de Guadalupe de Zacatecas were assigned to the new Nuestra Señora de la Luz Mission, which was also constructed in temporary quarters on the site of the trading post. Fray Bruno Chavira and Fray Marcos Satarain arrived there in November-December 1756. Both priests quickly fell ill. Satarain, a young man, was ordered by the older Chavira to travel to Los Adaes for treatment. The elder priest became ill himself and died on June 27, 1757, alone and unattended in his hut. He was replaced by Fray José Francisco Caro.
By the time of Chavira's death the mission consisted of a wooden church plastered with clay and moss. By the fall of 1759 the mission had been moved to a hill a quarter league to the east of the presidio. The second mission was constructed of hewn timbers plastered with beaten clay mixed with moss. The entire structure was then whitewashed. Both missions appear to have been roofed with palmetto. The presidio consisted of a varying number of buildings that generally included barracks, a captain's quarters, a store, a presidial church, and a central plaza. The presidio covered approximately 8,000 square meters.
On November 23, 1763, Capt. Rafael Martínez Pacheco was appointed commander of the presidio. The previous command of Lt. Domingo del Río (1756–63) apparently left the garrison in an undisciplined and demoralized state. Although Martínez maintained cordial relations with the Franciscans and the Indians, the soldiers regarded his command as cruel and arrogant. All but five soldiers deserted by August 28, 1764, and fled to Natchitoches. Upon hearing of the grievances of the soldiers, Governor Ángel de Martos y Navarrete suspended Pacheco and ordered Lieutenant Ruiz and a small force to El Orcoquisac to arrest the commander and relieve him of his post. Refusing to surrender, Pacheco and a handful of his cohorts fortified themselves within his quarters. After three days of unsuccessful negotiations, Ruiz and his force of twenty men set fire to the presidio on October 11, 1764, in an effort to flush out Pacheco. A pitched battle ensued, in which Pacheco and his men killed one soldier and wounded two others. The wily commander slipped out of a secret passage located in the chimney of his quarters and fled with a companion to San Antonio.
Ruiz was briefly installed as commander of the outpost and served until his arrest in November 1765 on charges of burning a royal presidio. He was replaced by Melchor Afán de Rivera, the next commander at San Augustín de Ahumada. Ironically, the command of the presidio was restored to Pacheco, who returned there on September 28, 1769. The commander who had left the outpost under the most disgraceful of circumstances had been cleared of responsibility in the burning of the presidio. He served until the place was abandoned in 1771.
The mission and presidio were ravaged by hurricanes in 1762 and 1766. The presidio was moved to a low hill about a quarter league from its original location. The Marqués de Rubí and a capable engineer, Nicolás de Lafora, made a formal inspection of the outpost in 1767. Rubí concluded that the post was of little strategic importance to Spain. His report, along with a comedic series of attempts to relocate the outpost over the course of its history, led to its abandonment in 1771.
Two centuries later an amateur historian from Houston, John V. Clay, ended several years of investigations by discovering the actual site north of Wallisville in Chambers County. His discovery in 1965 was followed in 1966 by an archeological mission led by Curtis Tunnell, which verified the site. An area including the mission, presidio, Blancpain's trading post, and about 200 Indian sites, to be known as the El Orcoquisac Archeological District, was added to the National Register of Historic Places in Texas in 1972.