In 1989, Judd purchased his last and largest ranch located 80 miles outside of Marfa. Las Casas ranch has two houses, a studio, a bunkhouse, lava rock corrals, and concentric circles of stone for a garden and tank. From 1989 to 1991, Judd continued to acquire property contiguous to the ranches, with the goal of preventing future development of the surrounding land. At the time of his death, Judd maintained nearly 40,000 acres, or 62-square miles of undisturbed ranch land. Judd was buried at Las Casas in 1994.
Prior to 1976, Judd had leased land south of Marfa to utilize for camping. He began purchasing large tracts of undeveloped land in the Presidio County region close to the Mexican border, on the north side of the Chinati Mountains in the Chihuahuan Desert. This land included existing structures, which Judd transformed into unique spaces that reflect his approach to rural architecture and land conservation. Judd named the ranch “Ayala de Chinati,” which includes three houses: Casa Perez, Casa Morales, and Las Casas.