San Bernardino Ranch, Historic cattle ranch in San Bernardino Valley, Arizona, United States.

San Bernardino Ranch is a historic cattle farming area in the San Bernardino Valley east of Douglas near the Mexican border. The property still contains original buildings from its operational period, including the main residence, a washing house, an icehouse, a grain storage building, and a commissary structure.

The 1822 land grant of 73,240 acres was a Mexican grant bought by Ignacio Perez for 90 pesos; Apaches drove him off in the 1830s. The Mormon Battalion crossed in 1846, and the Gadsden Purchase of 1854 split the land between the US and Mexico. In 1884 John Horton Slaughter bought 65,000 acres from Perez's heirs for about $80,000.

The ranch keeps the name of the San Bernardino Valley, given by Spanish missionaries who reached the site with Jesuit Father Eusebio Kino in 1694. Slaughter's household included his adopted Apache daughter, Apache May, who called him "Don Juan" and is buried in the cemetery on what is now the wildlife refuge.

The site sits about 15 miles east of Douglas in open terrain very close to the border. Plan a visit during cooler months, as the desert heat here can be intense during summer.

Slaughter's ranch hosted as many as 500 people, including many foster children. The best known was Apache May, an Apache toddler he adopted after finding her abandoned while tracking her band; she called him "Don Juan" and died at six when her dress caught fire. She is buried in the cemetery on what is now the wildlife refuge.