It is based on the true story of Juana Maria , the `` Lone Woman of San Nicolas '' , a Native American woman left alone for 18 years on San Nicolas Island off the California coast before being rescued in 1853 . This novel is based on the true story of Juana Maria , the `` Woman of San Nicolas Island '' , a NicoleÃ o Indian left alone for 18 years on San Nicolas Island , one of the Channel Islands off the California coast , before being discovered in 1853 .