The region presently known as the Hollister Ranch is defined by 14,400 acres (58 km2) of fallow and fertile fields, mountains and valleys along the Pacific coast of California between Gaviota State Park and Point Conception. It was the site of some of the oldest known human settlements in the new world, the last "native" population of which was the Chumash. The Spanish Portolà expedition, first European land explorers of California, traveled along its coast in 1769. It became part of the extensive Spanish land grant known as Rancho Nuestra Señora del Refugio, operated by the family of José Francisco Ortega from 1794.