Clepsydra Geyser serves here as a sunset pillar, helping paint this ethereal scene. What intrigues me the most is the lighter area at the base of the steam pillar, I didn't use flash and was the only one taking photos. I have no idea why it looks illuminated, spooky!
From the National Park Service:
This ( http://www.nps.gov/archive/yell/tours/fountainpaint/clepsydrageyser.htm ) nearly constant performer splashes from several vents and its steam can be seen throughout the Lower Geyser Basin. Its name is Greek for water clock, and was given because the geyser used to erupt regularly every three minutes. Since the 1959 Hebgen earthquake, however, Clepsydra erupts almost without pause. Sometimes it quits during Fountain's eruption.