Yorkshire's River Esk starts life as a series of streams known as “Esklets” on Westerdale Moor. The village of Westerdale is a row of 25 houses and the land has been farmed for a thousand years; barley, oats, turnips and potatoes were the main crops, but today grass, hay and silage for winter feed are concentrated upon. The soil varies in character from strong clays to free draining shales.
The Esk was once described “as this lovely brown fern-sided stream.” It often looks a murky brown deriving its colour from the varied strata over which it flows. In a valley where ironstone and sandstone are common, this is no surprise. Many becks entering the Esk contribute to the colour, but on bright sunny days with no spate water running and the light hitting the water at the right angle it can be remarkably clear. It then reveals the nooks and crannies that make it such a haven for sea trout and salmon to dwell in.
Clues to the tremendous forces that fashioned the topography are easy to find. Tilted shales, massive boulders, seemingly randomly thrown in the river and on its banks, give hints of upheavals in the past at which we can only guess. On top of this, tremendous floods in recent times have caused the movement of large quantities of sediments.
A member commented that "It is not only the geology of the Esk’s banks that delight the observant, but the flora and fauna constantly surprise. One day I very nearly stood on a young fawn. Noisy dippers and the raucous cry of the heron are small parts of the diversity of the birdlife. Foxes are regular visitors to the bank side. Otters now abound and occasionally one still sees a bank vole. Non-flowering plants, particularly after a shower of rain, as well as being treacherous underfoot, make a fascinating study. Liverworts and mosses and fungi are always in evidence. The daffodil and garlic seasons are always eagerly anticipated and a blank day in late summer can be saved by a good hatful of brambles. Hazel nuts too may be hoarded. It is truly a wonderland for anglers and nature lovers alike".