Turner went back to North Wales in the summer of 1799, armed with some large folded sheets of in addition to his usual bound sketchbooks. It was unusual for Turner to sketch in out of doors, but on this trip he made a number of large-scale studies on the spot, mainly showing the mountains of Snowdonia.
The vigorous brushwork of this sketch shows Turner's fresh observation of the scene. The practice of sketching from nature in watercolour became more common among British artists in the following decade.
Gallery label, September 2004