The A920 number is currently serving its third route, although still starting fairly close to its previous incarnation in Dufftown. This is that middle route, originally a part of the B9009, but renumbered by 1945 as the A920.
Starting on the A941 at Dufftown, the road headed northeastwards following the railway line (still in existence now as a preserved railway), meeting the B9115 en route. The road ended to the west of Keith town centre on the main A95 / A96 multiplex (originally the former number was dominant but now the latter is).
More recently, it was decided that the Dufftown to Huntly route was a more important or busier road, and so the A920 number was swapped with the B9014. This also enabled the extension of the A920 eastwards to the A90 at Ellon.