The center of a cattle ranching empire that straddled the U.S.-Mexico border, this ranch illustrates the continuity of Spanish and American cattle ranching in the Southwest. Until late in the 19th century, the San Bernardino Valley, a well-watered area occupying southern Arizona and northern Mexico, was not successfully occupied by Europeans due to the threat of Apache attack; in 1884, however, John H. Slaughter, a Texas cattle rancher, leased a portion of the Mexican land grant and began the development of a ranch that would span up to 100,000 acres, supplying beef, fruits, and vegetables to the surrounding settlements and military posts.

Information provided by the National Registry of Historic Places, a program of the National Park Service