Scarborough and Ryedale Mountain Rescue Team has been involved in the search for a missing Pickering man.
Nicholas Harper, 50, was last seen as he left his home in Pickering on Thursday morning.
His black Citroen Picasso was found parked about 13 miles away, at Cowbank Farm moorland car park near Helmsley.
Searches of a nearby forest and footpaths turned up "no signs of the missing man", volunteers said.
At the height of the search, 18 members of Scarborough and Ryedale Mountain Rescue Team and 27 members of Cleveland Mountain Rescue Team joined police dog teams and a force helicopter to search the area on Friday and Saturday. Five specially trained dogs from the Mountain Rescue Search Dog Association were also deployed.
Mr Harper's absence is giving police cause for concern.
He was last seen leaving his home address in Pickering in his black 15-reg Citroen Picasso to go to work in York at 7am on Thursday.
He is 5ft 5ins tall and described as of stocky build with dark brown short hair and a full beard. He is believed to be wearing a three-piece suit and shirt.
Tracks and forestry extending up to five miles from the car park were searched in an operation that lasted around eight hours on Saturday.
No signs of the missing man were found.