NN3163535419 Follow the private road downhill past Auch, crossing a bridge to meet a track crossroads (the West Highland Way). Go straight on, pass a cottage, ford the Allt Coralan (may prove tricky in flood) and continue into the Auch Gleann. At a track junction beneath the railway viaduct take the right hand track up Glen Coralan. Having passed some way above an attractive waterfall the track fizzles into rough pasture. Continue briefly up-glen, staying north of the burn.

NN3545534649 Curve left and climb onto Beinn a' Chaisteil's long southeast ridge. With an outlook over the precipitous face above Glen Coralan this is a great ascent route, and the summit offers airy views of the last peak on the round, Beinn Odhar. A dilapidated fence gives a general guide for the gentler descent northeast (not much trace of a path) into the peaty bealach of the Mam Lorn (not named on Landranger map) .

NN3560837643 Beinn nam Fuaran is a steep ascent, again without much path to speak of; the broken fence marks the best line, up left and then back right to outflank the roughest of the slope. From the summit cairn descend almost due south into the green glen of the Abhainn Ghlas.

NN3638836703 Cross the burn, then make the long grind up Cam Chreag's broad northern ridge. A cairn marks the highest of several rocky knobbles above the craggy east side of the hill. Descend roughly west-southwest through rocks and bogs to meet a disused electric fence that approximates to the northern perimeter of Loch Lomond and The Trossachs National Park and the Argyll / Stirling county line. A path follows the posts onto the next saddle.

NN3624133991 Continue up the northern slopes of Beinn Chaorach. The name means Sheep Mountain, and that does reflect its grassy character pretty well. From the summit trig point bear north and then west to descend the relentlessly steep slope into the glen below Beinn Odhar; the fence line is still visible, though following it exactly is no advantage.

NN3502333196 Still with the fence, more or less, continue west up the similarly uncompromising flank of Beinn Odhar to emerge on its gentler southeast spur. Climb this, past a level shoulder, to reach a tiny pool below the stony summit dome. A short steep climb now gains the cairn on top of the day's fifth Corbett. Go back past the pool to the shoulder, then descend a vague grassy spur east-northeast into Glen Coralan. Regain the north bank of the Allt Coralan and retrace your steps back to Auch.