Police have released a picture of a 67-year-old man who has gone missing.
Michael Peach left his home in Cuttholme Road, Chesterfield, at about 10am yesterday.
He was due to attend a fishing match at either Holmebrook Valley Park or Linacre Reservoirs but did not turn up at those locations.
The police helicopter was last night mounted to search for Mr Peach.
Mr Peach is white, with grey hair, of slim build and was wearing a blue Parker coat with a hood, grey tracksuit bottoms and trainers.
Police say he is a keen walker known to walk long distances.
Anyone with information on his whereabouts, or who might have seen him since 10am yesterday, should call police immediately on 101.