Not strictly defined, the hills form a lightly curving southwest–northeast shape and cover a considerable area.
The Ettrick valley to the east separates them from the Craik Forest and the western border follows the A708 road.
[1] The hills are relatively low-lying for the counties in which they lie, with the highest summit, Ettrick Pen, being 692m, however, unlike other nearby ranges, could be said to follow a definitive direction.
In a roughly southwest–northeast direction, the hills in the range over 2000 ft are: The area is renowned for its history, being part of the enormous Ettrick Forest, being the birthplace and frequent literary subject of the 'Ettrick Shepherd', James Hogg as well as the birthplace and workplace of Tibbie Shiel, among other things.
'Ettrick' is thought by W. F. H. Nicolaisen to be Proto-Indo-European, in reference to the Ettrick Water from where the hills and settlements take their name.