[1] From Ben Lawers National Nature Reserve car park (NN608379) – where donations for the upkeep of paths and the landscape are welcomed – walk through a gate, cross a road onto a path and climb gradually up to and through another gate. Go straight on and follow the signposted ‘Ben Lawers path’ north through the nature reserve. Keep along the path as it ascends gradually, alongside birch and rowan trees. The path soon bears right to cross a burn twice, and then a steady ascent proceeds beside a deer fence, with fine views across the glen to Meall Corranaich. In due course, the path swings right away from the burn (NN613392), but still follows the line of the fence to a gate. Once through this, continue to a fork.
[2] Take the right branch (NN616392) – left is the route of descent – from where a sustained ascent climbs northeast steeply up the lower slopes of Beinn Ghlas. The path is superb as it zigzags up the mountain, with great views opening out over Loch Tay and (once over a little crest) a fantastic aspect of Beinn Ghlas’ undulating top. A little respite is given as the path levels out, but not for long. Another steep, twisting ascent leads onto the rocky summit of Beinn Ghlas (NN625405) and a superb panorama that includes Ben Lawers and her craggy neighbours of An Stuc, Meall Garbh and Meall Greigh.
[3] From the top, continue northeast, with the ridge becoming narrower and an exposed drop to the left. A gradual descent between Beinn Ghlas and Ben Lawers onto level ground provides a little more respite, and there is the dramatic spectacle of Ben Lawers’ steep folded crags and slopes. As the route begins to climb, you pass a path on the left (NN630412). It is then a final steep pull up Ben Lawers’ rocky slopes onto its craggy, compact summit, adorned by a trig and cairn (NN636414). This is another terrific vantage point, where the views extend along Loch Tay to the distant cone of Schiehallion.
[4] Carefully retrace your steps back down to the path at the base of the slope. Bear right onto another superb path, where there are fine views towards Glen Lyon. The path meanders its way above the glen, contouring southwest around the lower flanks of Beinn Ghlas – keep an eye out for shielings in the glen below (shielings were huts used by shepherds for shelter during the summer months, when livestock grazed on higher ground). Once across a burn, the path soon sweeps right then left around the shoulder of crags to reach the head of the glen (NN622399), with the grassy slopes of Meall Corranaich rising to your right.
[5] From here, the path descends gently south through another glen to eventually return to the outward-bound path at the base of Beinn Ghlas. Turn right onto this and retrace your steps back down to the car park.