[1] It is part of a series of inter-connecting lochs and rivers that empty into Loch Laxford, which is a sea loch, the "ford" in the name meaning a firth not a ford[2] This drainage area, named the Laxford basin,[3] lies in the southern part of the civil parish of Eddrachillis (community council Scourie).

[1] The loch has a north-west to south-east orientation and is about 127 ft (39 m) above sea level.

[3] Loch nan Ealachan is a shallow basin up to 8 ft (2.4 m) deep joined to the main loch by a strait about 1 foot (0.30 m) deep, called Ùidh Dhubh (black ford[5]).

The volume of water has been estimated at thirteen million cu ft (370,000 m3).

Ben Stack (2,364 ft (721 m)), which rises steeply from the south side of Loch Stack, extends with a lesser incline as far as the hamlet of Achfary ( 154 ft (47 m)), by the shore of Loch nan Ealachan.