A loch of the Inverness district of Highland Council Area, Loch Mohr is located 2 miles (3 km) southeast of Loch Ness, above Foyers, and 10 miles (16 km) northeast of Fort Augustus. The loch was created by the British Aluminium Company in 1896 by joining two smaller lochs (Loch Garth and Loch Farraline) to provide a reservoir for their hydro-electric power plant at Foyers. Loch Mhor now forms the upper reservoir for the Foyers Hydro-Electric Power Scheme, which is primarily a pumped-storage scheme. The reservoir is retained by masonry and embankment dams which were strengthened for the new scheme.
In 1841, several muskets were discovered in Loch Farraline, thought to have been disposed of following the Jacobite Rebellion on 1745 and, in 1973, while the water level was lowered to permit reconstruction, a crannog, or ancient loch dwelling, was discovered here.