In Ptolemy’s description map of Scotland the Caledonians occupied the area down the Great Glen. It may actually have been all the highlands. The maps below mentions tribes that are never again refenced in Roman literature. Note the first map is from 1476 and the Roman had the orientation of Scotland wrong sp that it lies on its side. These maps do not mention the Maeatae tribe near Stirling which are referred to in other Roman literature.
The Caledonians have been mentioned in inscriptions elsewhere – this one below from the year 222 says “To the god Mars Medocius of the Campeses and to the Victory of our Emperor Alexander Pius Felix, Lossio Veda, grandson of Vepogenus, a Caledonian, set up this gift from his own resources.”