According to author and historian Don Beers, despite the fact that the offical name is Southesk Pass, "for decades everyone in Jasper Park has called it Cairn Pass."
James Carnegie (Earl of Southesk), travelled over this pass in 1859 on his way from the Athabasca River valley to the Bow valley.
James Carnegie (The Ninth Earl of Southesk) travelled to Canada in 1859, thinking that it would improve his deteriorating health. He travelled extensively through the foothills and Rockies. In 1875 he wrote, "Saskatchewan and the Rocky Mountains" which described his travels along the river and in the Rockies.
During his 1859 trip, The Earl of Southesk and his friends climbed Southesk Cairn, a low mountain immediately southwest of the pass and built a giant cairn on top that can still be seen today. He wrote in his journal, "I am the first European who has visited this valley, and if I might have the geographic honour of giving my name to some spot of earth, I should choose the mountain near which the two rivers rise." However he was concerned that the peak he had chosen near the source of the Medicine Tent and Southesk Rivers might be visible from another valley and already named. But no one could dispute the one that he had climbed so it carries the name Southesk Cairn Mountain. The mountain that was his first choice also carries his name as Mount Southesk.