short for
Yellowstone National Park, over 3,000
square miles of parkland in the western United
States containing
geysers,
hot springs, lakes and waterfalls, etc.
And it's going rahr- rahr-rahr-rahr dhu-dhu-dthu, bop, plop, you know, and it looks like one of Yellowstone Park's geysers, you know, about to explode and so on.