[3] 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.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.The proper route from the south top is to go initially west for a short distance across a hollow and onto the ridge which leads north to the main summit.[7] Hamish Brown recommends a northern approach starting at Auch (grid reference NN324355) “if you want to be different” but this requires good navigation and some mild scrambling up the north west ridge.[8] The actual summit of the mountain is named as Stob Glas (greenish-grey peak) on maps and has a large cairn which overlooks the sheer northern face.