There's a great aerial photo of the Grand Prismatic Spring in the book Earth From Above. So Addie wanted us to have a look - and it was well worth stopping. Descriptions and pictures (even professional ones) don't do the colors justice. Don't even mention the smell!
We spent a more leisurely day investigating geothermal formations in the park yesterday. A lot of these geyser-ish sights are way more impressive than Old Faithful in terms of colors, smell, level of activity and other-worldliness.
If I ever figure out how to post video I'll put up some moving pictures of these things.
We also drove Grand Canyon loop through what felt like rush hour traffic. We managed a one mile hike with the payoff of this great view of the Lower Falls. The relatively steep climb nearly landed one or two of us (ahem) in the local ER but we lived to blog the tale, luckily.
More Yellowstone weather: On our way out of the park in the evening we got clobbered by a hailstorm that came out of absolutely nowhere. It began with two big thunks on the windshield and went from zero to sixty almost instantly. The temperature plummeted from the mid 80's to 52 in a matter of minutes. And then, just as suddenly, it was over. We drove out into West Yellowstone in lovely sunshine.