This is the American West as a dream. Bierstadt, a German-born painter, travelled west with surveying expeditions in the 1860s and came home with sketches of mountains, lakes and valleys that most Americans would never see. Then he turned them into vast theatrical canvases — this one is about two by three metres.

It isn't a real place. It is a composite: a perfect lake, a perfect cliff, a perfect waterfall and a perfect sunburst through parting storm clouds, arranged for maximum awe. Strangely, Bierstadt painted it in Europe, and exhibited it there before it came to the United States.

His critics called it showmanship, and they had a point. But paintings like this helped persuade city-dwellers back east that the western wilderness was something extraordinary — a feeling that fed into the movement to protect places like Yosemite.

Look at it as you might look at a really good gig light show: not accurate, just overwhelming, on purpose.