Kyle Sambrook, 33, was seen with his beagle called Bane in the Lost Valley area of Glencoe at about 12pm on Sunday and police are keen to speak to anyone who may have seen him in the area at the time.
He travelled in his black Peugeot 208 from West Yorkshire on Saturday, February 18, and arrived in Glencoe at about 3.30pm the same day.
Police say he has not been in touch with his friends or family since.
It is believed Mr Sambrook intended to walk and wild camp in the area before returning to Yorkshire on Tuesday, but he failed to return home.
Concerns are now growing for his welfare and extensive searches have been ongoing to trace him.
Sergeant Shaun Knox said: “Kyle was suitably clothed for walking and we believe he had a tent and other equipment with him.
“He may have changed his original plan to climb Buchaille Etive Mor and it is important that we find him to make sure he is safe and well.
“We are asking anyone who was out and about on Sunday in the area, and in the days since, if they recall seeing Kyle and his dog, both are quite distinctive.
“We would like to thank everyone who has responded to our appeal as every piece of information, no matter how small, could be vital in helping us to find him. Please get in touch with any information that you might have.”
Mr Sambrook is described as white, 5ft 8ins, of medium build, with ash blond short hair, ginger/blond stubble, blue eyes and a West Yorkshire accent.
At the time he went missing, he was believed to be wearing khaki and black Merrell hiking boots, khaki and black Revolution Wraith outdoor trousers, a dark and light blue hooded Peter Storm waterproof jacket and grey North Face beanie hat. He was carrying a grey and yellow Merrell backpack.
Anyone who can help should call Police Scotland on 101, quoting reference number 1644 of Wednesday, February 22.