Glen Orchy runs from Bridge of Orchy on the A82 to Dalmally on the A85. A narrow road follows the River Orchy through the glen. Parking for Beinn Bhreac-liath and Beinn Ulaidh is by a bridge over the Allt Ghamhnain and next to a gate accessing the thick adjacent forest. Parking for the route up Beinn Mhic Mhonaidh is by the bridge at the Eas Urchaidh, or alternatively 100 metres to the north in a layby.
From by the bridge over the Allt Ghamhnain, cross north and walk until a gate is met. Head through the gate and up a track towards the house at Invergaunan. As the house is approached, look for a faint path heading to the base of the hill directly ahead. The path gradually fades into the grass. On pathless terrain the going underfoot is pleasant on the flatter ground. Continue up the north-west shoulder of Beinn Bhreac-laith and as the 700m contour is reached, the ground levels out and it's an enjoyable walk continuing to the summit while enjoying the views, particularly back towards Beinn Dorain. A few false summits are passed to reach a small cairn marking the hill's summit. Fine views in all directions.
From Beinn Bhreac-liath's summit, turn south-west and drop on grass and rush covered gentle slope to the bealach below with its small lochan. Continue south-west and begin to climb. Easy at first, the route then appears to initially curve around some rocks, but a faint path can be found to clamber over them. Head northwards on the plateau and a large cairn with the remains of an abandoned mast are met on the summit.
Head northwards for a bit, then start to lose height. Some large rocks protruding out of the otherwise grass covered slopes will be encountered. These rocky outcrops form the quartzite dyke that can been seen from the north forming a long unusual line up Beinn Ulaidh's northern shoulder. Contained in the rock is a tiny amount of gold (click here
for more info) ! Follow this line of rock downhill to meet the Allt Ghamhnain, then head north-west through grass and trees back to the road.