The 22-year-old has not been seen since February 11 and police and Land Search and Rescue teams have done extensive searches around Alexandra, particularly to the east of the township, near the Manuherikia River and in the area behind the clock on the hill.
They have also searched the banks of the Clutha River from Alexandra to the Roxburgh Dam.
Mr Bates' family and friends have also been helping with the search. A specialist dog team is also assisting.
Senior Constable Craig Gibson, who is heading the operation, said Alexandra residents were being asked to "keep an eye out" for Mr Bates and search garden sheds, garages and outbuildings on their properties, both in town and out of town.
They were also being asked to contact police if they noticed anything unusual in river or hill areas around Alexandra.
Any businesses with CCTV cameras were also being asked to check them, particularly footage from Sunday February 11 and Monday February 12.
Mr Bates was thought to be on foot, but it was possible he could have used public transport to travel out of Alexandra, Snr Const Gibson said.
Mr Bates is described as being of slim build, about 180cm tall, with short to medium length brown hair and brown eyes.
He was wearing a grey hoodie, white T-shirt, dark shorts and sneakers.
