Sunset Lake is located in Black Sand Basin of Yellowstone. Sunset Lake has been active as a geyser intermittently for many years. In August 2000 it was almost continuously active, erupting every few minutes.
Sunset Lake August 2000 far:

Sunset Lake movie (0.3 Mb, 7 sec)
Sunset Lake August 2000:

Sunset Lake movie (0.5 Mb, 11 sec)
Sunset Lake August 2000 from the observation deck:

Sunset Lake movie (0.4 Mb, 8 sec)
Images copyright 2000, Michael Frazier. All rights reserved.