Looking from the head of Loch Treig on the left and to the north on th right. The railway line to Fort Willaim follows the tree line on the right.

Water taken from Loch Treig, Spey, and Loch Laggan dams is passed through a 15 mile long tunnel to the Lochaber power house. It produces the largest net output of any hydro-electric installation in the UK, powering the Lochaber smelter with 12 main generating sets each producing 3.5MW for the smelting process.