Map & Elevation
About this Route
This out-and-back reaches Sgùrr Mhòr, the highest summit of Beinn Alligin, from the car park beside the Abhainn Coire Mhic Nobuil. The GPX measures 9.8 km, gains 1,289 m and gives a walking-time estimate of about 4 hours 35 minutes. Six to eight hours is more realistic for the steep ascent, rocky ridge and the return over Tom na Gruagaich.
Cross the footbridge and follow the good path into Coire Mhic Nobuil. At the path split, turn into Coir nan Laogh and climb towards Tom na Gruagaich. The upper corrie is steep and rough, with a worn path leading onto the ridge. Turn north to reach Tom na Gruagaich's 922 m summit.
Continue along the main ridge, descending and then climbing towards Sgùrr Mhòr. The ridge is rocky and exposed in places. Eag Dubh, the deep Black Notch, cuts into the mountain below the crest and is a useful landmark, but keep away from its edge. A final climb reaches Sgùrr Mhòr at 986 m.
This guide turns around at Sgùrr Mhòr and retraces the route over Tom na Gruagaich. It does not continue over the Horns of Alligin, which involve exposed scrambling and form part of the full horseshoe. The return includes substantial re-ascent and a steep descent into Coir nan Laogh, so keep time and energy in reserve. Carry full navigation equipment and avoid the ridge in strong wind, thick cloud or winter conditions unless properly experienced and equipped.
The quickest and easiest return is by the route of ascent.
Mountaineering Scotland
Route Waypoints
Start beside the Diabaig road and cross the footbridge onto the main hill path. Check the correct return bridge now, as several burns join lower down.
Follow the good path upstream between Beinn Alligin and Liathach. Stay with Coire Mhic Nobuil until the signed or mapped split for Coir nan Laogh.
Take the branch into Coir nan Laogh; the Horns path is not the route used here.
Climb steep, rough ground on the worn path towards Tom na Gruagaich's ridge. Loose stones sit on the upper path, so leave space between walkers.
Reach the 922 m Munro and turn north along Beinn Alligin's main ridge. Note the descent back into Coir nan Laogh before continuing.
Cross the rocky ridge near the Black Notch, keeping safely back from steep edges. The return crosses this same ground, including the re-ascent to Tom na Gruagaich.
Reach the 986 m summit and turn back; do not continue east towards the Horns.
Retrace the ridge, recross Tom na Gruagaich and descend Coir nan Laogh to the car park.
Essential Tips
Turn around on Sgùrr Mhòr. The Horns involve exposed scrambling and are outside this guide.
The way back includes a clear re-ascent over Tom na Gruagaich before the long corrie descent.
The Black Notch is a striking landmark but has very steep ground below it. Stay on the ridge path.
Exposure, rock and poor visibility make the high section much more serious than the distance suggests.
Frequently Asked Questions
How long does it take to climb Beinn Alligin via Sgùrr Mhòr?
Six to eight hours is realistic for the full route. The GPX estimates about 4.5 hours, but that doesn't account for the steep ascent, rocky ridge sections, and substantial re-ascent on the return over Tom na Gruagaich.
Is the Beinn Alligin ridge walk dangerous in bad weather?
Yes, you should avoid the ridge in strong wind, thick cloud or winter conditions unless you're properly experienced and equipped. The exposure, rocky sections and poor visibility make it much more serious than the distance suggests.
What is Eag Dubh on Beinn Alligin?
Eag Dubh is the Black Notch, a deep cut into the mountain below the ridge crest. It's a useful landmark but has very steep ground below it, so you need to stay on the ridge path and keep well back from the edge.