In 1629, Fray Francisco Letrado was sent to the pueblo of Las Humanas, also known as Gran Quivira. With the assistance of Fray Diego de San Lucas, Letrado successfully negotiated with the pueblo leaders to use eight rooms located on the southwest corner of Mound 7 Pueblo. To make these rooms more suitable for his needs, he modified them by enlarging some doors, sealing others, constructing an altar, and adding more windows for better lighting. This area, now known as Letrado's Convento, was the first church used for conversions at Gran Quivira.
Letrado and Diego spent the winter in Santa Fe and returned to Las Humanas in the spring of 1630 with two or three wagon loads of supplies. Once again, Letrado negotiated with the pueblo leaders, this time securing a work crew to help expand his space. They built an additional eight rooms, effectively doubling the size of the convento. During this period, Letrado also began work on the larger San Isidro Church. Sadly, he would not live to see it finished, as he was transferred to the pueblo of Hawikuh near the Zuni Pueblo, where he was killed during an uprising. Letrado had worried that Las Humanas couldn't support a large mission due to a significant water shortage, leading it to become a Visita, or satellite mission, of the Abó Mission.
In the 1960s, Letrado's Convento was excavated as part of the Mound 7 dig. Artifacts from this excavation are now displayed at the Gran Quivira Visitor Center. After Mound 7 was backfilled in 2012, the rooms of Letrado's convento remained open, providing a clear view of the differences between the pueblo rooms and those constructed by the Spanish during the early conversion efforts at Las Humanas.
