There are two popular routes for Beinn Mhanach. One is from near Auch, with parking on the A82 near the private road, up Auch Gleann and past Ais-an-t-Sidhean. To reach the summit dome of the mountain the slopes to the north-east of Beinn a'Chuirn are traversed. The other route starts from Achallader farm at grid reference . This route is often taken when the nearby Beinn Achaladair and Beinn a' Chreachain are climbed.