The Sierra Bonita Ranch, founded in 1872 by Henry C. Hooker, is one of the oldest cattle ranches in the United States and the ranch buildings have been designated a National Historic Landmark. It was the first permanent American cattle ranch in Arizona. Hooker bought neighboring ranches until his operation became the largest ranch in Arizona, totaling 800 square miles (2,100 km2), or about 30 by 27 miles (48 by 43 km). It is located in Sulphur Springs Valley about 27 miles (43 km) north of present-day Willcox, Arizona. The modern ranch is much smaller but is still operational and owned by Jesse Hooker Davis, the sixth generation to live and work on the ranch.