Historically the Lairig Ghru has been used simply as a route between Deeside and Strathspey. It is often referred to as a Drove Road, and while it's not wrong to do so, arguably that over-emphasises one specific use. The Lairig Ghru has been a route used by many different people, for many different purposes as made clear in "Haldane (1952)", and was in regular use long before the height of the droving trade in the more peaceful times after the middle of the 18th century: