The River Dee rises at an altitude of 1220m on the extensive semi-arctic Braeriach-Cairn Toul plateau in the Cairngorms National Park. It originates from a series of springs (the Wells of Dee) at the foot of a bank of grass and moss, then cascades off the plateau in the Falls of Dee. Its earlier source, further west, in the Glens of Tilt and Feshie were dammed by moraines and diverted, respectively to the Rivers Tay and Spey.
For the majority of its course the River Dee flows eastwards through a valley which broadens and becomes much gentler in relief nearer the coast. The foothills of the Cairngorms extend to the sea, particularly to the south of the valley. The notable characteristics of the river include its great altitudinal range, and its unique succession of plant communities. Steep in profile compared with most other large British rivers, much of the river runs over gravel or cobbles, and there is virtually no lowland ‘depositing’ section. These features make the River Dee, its tributaries and lochs of considerable interests to scientists.
The River Dee itself is considered to be the best example of a large natural highland river in Scotland. Its headwaters are among the highest of any major river system in the British Isles.
The main tributaries of the river are the Lui, Clunie, Gairn, Muick, Tanar, and Feugh. With the exception of the Water of Feugh these watercourses enter the river relatively high up the catchment.
There are few standing waters in the catchment, but several are large. Examples are Loch Muick and Loch Callater both in deeply glaciated mountain troughs and dammed by moraines and, in contrast, the eutrophied Loch Skene, a giant kettle hole lowland loch.