"We contacted neighbours and got them to have a look and check their properties but there was nothing," said Chris Browne.
Northland police put out an appeal on social media for sightings of the missing man.
"The police were concerned he might have been picked up by someone and taken to hospital," Chris Browne said. "It was a pretty sleepless night."
About 8am yesterday the family were searching along a river in thick bush calling out to Mr Browne when he replied.
It appeared he had tried to find his way home and taken a short cut through the neighbour's property when he slipped down a steep bank into dense bush.
"I heard him call out and I couldn't believe it," Chris Browne said.
He found his father warm and dry under a thick canopy of ponga and tea tree.
"He was a bit muddy and had a few scratches but was surprised we were looking for him."
Detective Paul Overton, and member of the Whangarei police Search and Rescue squad, said the Coastguard plane had also been notified and was going to fly over a nearby estuary when the good news filtered through that Mr Browne had been found.
A team of eight LandSAR volunteers had joined the police Search and Rescue squad and had mapped out a large area to search.
"The family had already started to search and found him at the bottom of a steep gully. It was really good to find him so early on," Mr Overton said.
The teams carried Mr Browne on a stretcher to a waiting ambulance and he was taken to Whangarei Hospital and checked over before being released yesterday afternoon.
The family were considering using a tracking device called Wandatrak.
The Wandatrak, worn by a person, is a small pendant which emits a pulse that is detected using a radio tracking unit and a directional finding aerial. As the tracking unit gets closer to the pendant, the pulse becomes stronger.
Inherent memory loss means six out of 10 people with dementia wander, and police are encouraging patients to wear a tracking device.
Each pendant has a unique code which is logged on the police computer system. Police can also hold extra information about users of the system that helps search teams to find missing people faster.