Bison in the Mist Above a Frozen Thermal Stream

A single dark bison stands in the upper left of the frame, its shape softened by a thick bank of steam drifting across the scene. Below it, a shallow stream winds through white snow, its water slate grey and its banks edged with rust-brown mineral staining and frosted crystals. Snow-covered ground fills the foreground and right side, while a few conifers fade into the haze along the top edge. The palette is almost monochrome, with whites, soft greys and a little warm brown, and the mood is quiet and cold.

The photograph was taken in Yellowstone National Park, where the outflow from Terrace Spring carries warm water over the ground. Heated runoff keeps channels open and steaming in winter, and the colour of the banks often comes from mineral deposits and heat-loving microbes. Bison are North America's largest land mammals. They stay in Yellowstone through the cold months, using their heavy heads to sweep snow aside for grasses, and they often favour thermal areas where the ground is clear and warmer. The pale, low-contrast tones and open space at the top suit a widescreen desktop monitor, where desktop icons will not crowd the small figure of the animal.