Flowing Fog

This was an unusual phenomena that I was lucky enough to witness. The valley on the other side of the pass (upper right of photo) was approx. -35°F and completely full of ice fog. This side was about 10°F. The cold ice fog was overflowing the pass and pouring down the mountainside in a narrow stream at the rate of approx. 30 - 40 mph. The air around the stream was relatively still. It was like a fast flowing river of fog.