The Yana Indians lived in northeastern California just east of the Sacramento Valley and were divided into four adjoining sub-groups: Northern Yana, Central Yana, Southern Yana, and Yahi Yana. The Yahi Yana, commonly known as the Mill Creeks, lived in a wild region along Mill and Deer Creeks of cliffs, gorges, glens, caves, and dense brush, where they remained undisturbed until white settlement began in the Sacramento Valley. According to neighboring tribes, the Yahi were aggressive and warlike, with continual disputes with their neighbors, and they sometimes raided remote homesteads for food, cloth, and livestock to avoid starvation. From 1860 to 1870, the Yahi suffered numerous brutal massacres, some directed and financed by the U.S. Army in response to outrage over raids and murders blamed on them, and others carried out by settlers or paid vigilantes. These continual acts of genocide forced the Yahi into the most inaccessible parts of the Mill and Deer Creek canyons and sharply reduced their hunting and food-gathering territory. During the next 40 years, from 1870 to 1910, only a few sightings of wild Indians were reported, and although most people believed the Yahi were extinct, they survived in their traditional way of life for more than a generation before dwindling to fewer than six individuals. On August 29, 1911, the last surviving Yahi was captured at a slaughter house outside Oroville, nearly naked and starving, and taken to the jail in Oroville, where crowds came to see him but could not communicate with him. By hand signals he indicated where he was from and that three companions had died on the journey. Professor T.T. Waterman of the University of California at Berkeley met him, confirmed the reports, and used a list of Northern Yana words that he understood before taking him to San Francisco, where a Northern Yana helped interpret his language. At Professor Kroeber's suggestion, he was nicknamed Ishi, meaning man in the Yahi language, and he lived for five years at the Museum of Anthropology at UC Berkeley. His real name was never learned because the Yana believed an actual name carried power and magic and was too intimate to share. During one museum outing to the beach, seeing the ocean for the first time, Ishi exclaimed, "Bansi saltu!" meaning many white people, showing his amazement and alarm after spending most of his life hiding on Deer Creek with only five people left in his tribe. He remained at the museum until his death from tuberculosis on March 25, 1916, after which his body and some of his most personal possessions were cremated according to the custom of his people. In 1984, the United States Congress enacted the California Wilderness Act, Public Law 98-425, designating the 41,100 acre area as Ishi Wilderness.