Assistance from Northumberland National Park Mountain Rescue Team (NNPMRT) and North of Tyne Mountain Rescue Team was requested by Northumbria Police around 3.45pm.
While Mountain Rescue personnel travelled to the area, the incident officer was able to achieve contact with the walkers on their mobile phone.
After descending below the cloud, the walkers were able to take a photo of what they could see which was sent to Mountain Rescue, which ascertained their location as the upper area of the Harthope Burn.
Two team members were dispatched to meet the walkers as they descended to escort them off the hill and for onward transport to their own car.
The mountains of the UK, including those of the Northumberland National Park, often have poor mobile-phone signal making it difficult for those needing help to request it. It is sometimes possible to send a text when it is not possible to make a phone call.
The emergency services can be contacted on 999 via text in an emergency, provided the mobile phone has been registered to use the text service.
The teams strongly encourage anyone walking on the hills to register their phone and instructions on how to do this can be found at www.emergencysms.org.uk
The incident involved 18 volunteer Mountain Rescue team members for just over two-and-a-half hours.