Golden Gate, Yellowstone National Park

A stagecoach rolls along a wooden trestle road bolted to the side of a cliff, tiny against walls of rock that glow orange in low sun. This is the Golden Gate, a narrow canyon on the route between Mammoth Hot Springs and Norris in Yellowstone, and the road really did look like this: engineers pinned a timber viaduct to the rock face in the 1880s because there was no other way through. That pale stone column standing at the road's edge is the Pillar of Hercules, a landmark still there today. Thomas Moran painted the scene in 1893, and it is a curious mix of wilderness grandeur and infrastructure advertising, since the Northern Pacific Railroad had a strong interest in convincing Americans that Yellowstone was worth the ticket.

Moran belongs to the Hudson River School tradition carried west, where enormous skies, golden haze and deep shadowed valleys were used to make landscape feel like scripture. He earned the right to paint this place: he traveled with the 1871 Hayden Survey, and the watercolors he brought back helped persuade Congress to create the world's first national park the following year. He was so linked to the region that he signed his work with a monogram reading T-Y-M, the Y standing for Yellowstone. Look at the boulders in the foreground, painted with far more attention than the misty gorge behind them, and you get a sense of how he built these scenes: solid, touchable rock up close, dissolving into atmosphere and light the further back you go.