[1] It is a shallow flat-bottomed basin, in common with most of the nearby lochs.

The latter is formed by a union of Rumsdale Water (source Rumsdale Loch) and Glut Water, whose source to the south-west is at a height of around 1,400 ft (430 m), about 14 miles (23 kilometres) upstream from Loch More.

However, in 1907-1908 a dam was built at the outflow into the River Thurso, which raised the level of the loch by 12 ft (3.7 m).

Its purpose was to control the amount of water in the downstream River Thurso, thus improving the quality of salmon fishing.

As a result, the area of the loch increased to 511 acres (0.8 square miles; 2.1 square kilometres), with a depth up to a maximum of 27 ft (8.2 m), depending on the amount of water discharged.