Beinn Challuim is often regarded as a smooth grassy hill mainly because these are the characteristics of the southern and western slopes which are seen by many people from the A82 road around Strath Fillan. However from the north it shows a more exciting form with a steep and rocky face overlooking the head of Glen Lochay. Beinn Challuim is made up of three ridges, the broad grassy south west ridge descends to Strath Fillan and is used in ascents from there. The north west ridge is steep and rocky and descends to the Bealach Ghlas-Leathaid (575 metres) and then connects to the Corbett of Cam Chreag. Another ridge goes easterly, descending into Glen Lochay.