Hot Stuff at Yellowstone

So, everybody knows that most of Yellowstone National Park is actually a huge caldera of an active volcano, right? Not active, you say? 

Check out all the thermal stuff going on there, including, of course, Old Faithful.

How big is the volcano, you say? The caldera is approximately 35 MILES in diameter! 

It's last major eruption ejected 240 cubic miles of dust, rock, and lava. That was 640 thousand years ago, so no worries, right? Don't bet on it! Less than 6 years ago a huge bulge in the park rose 8 inches in less than a year. That's how Mt St Helens started. Only this volcano, in a previous eruption, spat out 2500 times what Mt St Helens did! Yeouch! The main observable feature of the volcanic nature is hydrothermal. Hot, dangerous, and beautiful!

This is the Steamboat Geyser, which is irregular, but has sprayed boiling water and steam over 300 feet high.

This is a mud pot, sulphur gas and steam bubbling up through fine clay.

Looks like lava flowing into the river, but actually it is steam and hot water. Don't try to swim there, though.

A huge vertical shaft of cooled magma, the surrounding soil has been eroded away.

These beautiful but deadly hot and acidic pools are called the paint pots.

OK, so I "tweaked" this one a little, but doesn't it look like a tortured face screaming from the stone cliff?