When the Spanish settled present-day Arizona, the Santa Cruz River valley provided them with fertile land and new potential converts for the Catholic Church. They built a chain of missions, forts, and small outposts along the river to establish a presence in New Spain. The Spanish imported their culture to the region by sending European priests to work with the Pima people, who lived near these settlements. Tumacácori National Historical Park in southern Arizona near the Mexican border manages and preserves evidence of Spanish settlement in the Pimeria Alta mission province. San Cayetano de Calabazas, a National Historic Landmark located within the park, is a significant site of adobe ruins where Spanish culture was introduced to the Pima and which was later occupied by acculturated Pima, Mexicans, Americans, and Mexican-Americans.

Spanish Jesuits founded San Cayetano de Calabazas in 1756 after reorganizing their settlements in the wake of the 1751 Pima Revolt. Though it served many different purposes in the years between its founding and the late 19th century, Calabazas was first intended to be a “visita,” a station for visiting priests to reside as they traveled between missions throughout northern New Spain. As a visita, Calabazas was a satellite outpost associated with larger Mission Guevavi and later with Mission San Jose de Tumacácori, which were part of a string of missions throughout the northeastern Sonoran Desert. It is the most complete extant Spanish colonial mission district and best preserved remains of a visita in the United States.

The Spanish Catholic visita at Calabazas lasted 30 years, between 1756 and 1786. During this time, Catholic priests baptized, married, and buried Piman residents and exposed them to Spanish culture. This acculturation of American Indians at Spanish missions was an essential part of Spain’s colonization strategy. At Calabazas, missionaries gathered together Piman residents and introduced them to European animal husbandry, European crops, the Spanish language, Catholicism, and European social values. The new food sources, like wheat and cattle, allowed the Pima to concentrate their population at water sources where the Spanish established missions and visitas. This increased the food yield for the Pima, but disease spread quickly among the American Indians there. To keep Calabazas running, the missionaries encouraged the neighboring O’odham to join the remaining Pima. However, Western Apache raids in the region forced the Spanish to abandon Calabazas in 1786, and its residents dispersed.

In the 19th century, Spanish and Mexican alliances with accommodating Apache and Pima made Calabazas safe for settlement again. Piman ranchers obtained Calabazas in 1807 for their herds of cattle, horses, goats, and sheep. The mission outpost was also reestablished at that time and Franciscans returned to serve the community for a short time. Calabazas began to decline after the Republic of Mexico expelled the Spanish-born priests in the 1820s.  The Piman mission ranch at Calabazas lasted until January 1830, when it was abandoned after Apache raiders set fire to the buildings. In the 1840s, the governor of Sonora, Manuel Maria Gandara, acquired Calabazas and established a hacienda there where Mexicans, acculturated Pima, and German immigrants managed the ranch. In 1853, the United States acquired Calabazas from Mexico as part of the Gadsden Purchase. The threat of Apache raids and political transition drove the German ranchers out by 1856.

San Cayetano de Calabazas mission ruins in Tumacácori National Historical Park. Courtesy of the National Park Service

Twice during the 1850s and 1860s the U.S. military settled at Calabazas to help stabilize the region. In 1856 and 1857, the 1st Regiment of Dragoons under Enoch Steen lived in the old adobe buildings and called the base Camp Moore. This regiment fought to protect Americans, Mexicans, and Pimas from Apache raiders. Due to Camp Moore’s protection, civilians in the Calabazas area were able to establish gold mines and ranches. The second military occupation of Calabazas was during the Civil War, in 1864, when volunteer soldiers from California built Fort Mason. The military force at Fort Mason included the only regular Army unit in which all the officers and men were Mexican-Americans. They replaced regular troops who were sent east to fight in the war after the immediate Confederate threat to the Southwest ended. This volunteer company suppressed Western Apache raiders and assisted the Juarista governor of Sonora against the French incursions into Mexico.

Calabazas was also the site of a U.S. Customs office for a short time between the military occupations. William Mercer, the regional deputy customs director, set up the old visita as a U.S. Customs House. Customs agents at the adobe chapel building inspected goods traveling between the United States and Mexico. Mercer stayed at Calabazas until the start of the Civil War, when troops were sent eastward and Apache pressure forced the office to close.

After the War, Calabazas changed hands multiple times as the American government determined the legality of private land claims within the Gadsden Purchase. Ultimately, in 1964, the land was sold to the Gulf-American Corporation. Calabazas was entered into the National Register of Historic places in 1971 and the corporation donated the land to the Arizona Historical Society in 1974. Calabazas was made a National Historic Landmark and incorporated into the Tumacácori National Historical Park in 1990.

The ruins of San Cayetano de Calabazas are located on an elevated terrace east of the Santa Cruz River. Today, two adobe buildings remain standing. One of these adobe buildings is the original Spanish visita chapel, which is surrounded by a stone wall. The other adobe building is a long rowhouse north of the stone enclosure and visita. The rowhouse was built during the mid-19th century and probably used as a ranch barracks at that time. An archeological survey in the 1970s determined that, in addition to the visita structure and barracks, at least eight smaller buildings with stone foundations once stood in the Calabazas district. To preserve this valuable cultural resource, the ruins of Calabazas are restricted and can be visited while on a reserved guided tour with a NPS ranger or volunteer during winter months.