[Image]  We started off Day 4 going to the Midway Geyser Basin, one of my favorites. We got there before it was really busy, and the steam coming off the hot pools made an incredible fog.

[Image]  The highlight of this basin is the Grand Prismatic Spring, the largest hot spring in Yellowstone, and one of the most colorful. You can see some of the colors reflected on the steam.

[Image]  The patterns the hot water and bacterial mats make are fascinating. I could spend a lot more time looking at them!

[Image]  Off in the distance is even more steam rising, giving hints that this is a hot place.

[Image]  The kids were good about posing for a photo. What sweeties!

[Image]  And another, with the fog behind them.

[Image]  Desert Girl fortunately was very good about staying on the boardwalk. She did get on her belly to get a closer look.
[Image]  We saw a dragonfly dead on the bacterial mat.

[Image]  We also saw some bison tracks. I guess they didn't read the signs about staying on the boardwalk.

Next we headed to the Old Faithful area, which was a zoo. We went to the new visitor center and signed Desert Boy up for the Young Scientist program. We checked out a backpack with an infrared thermometer, stopwatch, magnifying glass, and rock samples. Then we headed down the path on our bicycles. The kids loved a change from hiking. So did I!

[Image]  We found that Riverside Geyser was supposed to erupt soon, so we waited, and in the meantime Desert Boy started measuring the temperature of everything he could find. He didn't really know what the numbers meant, but it was a cool gadget. He shared with a family that was waiting in the shade with us, and they enjoyed it too.

[Image]  He used the magnifying glass to get a closer look at the rock samples. It was a fun program, and I think he might have learned a little from it.

[Image]  Then Riverside Geyser began spewing water. It was beautiful! The eruption lasted more than 20 minutes, but folks watching it mostly lasted half of that before they started wandering away.

[Image]  We went to the end of the bike path and saw the beautiful Morning Glory Pool.

[Image]  On the way back it looked like Castle Geyser was going to go off, so we stopped. Desert Boy walked around to the side to get a better vantage point to draw the geyser.

[Image]  Little splashes of water teased us.

[Image] Finally it went off in a minor eruption. It seemed big to us!

It was a fun morning, and the bikes made a big difference. We had ample people-watching time. So many people looked like they just hung out for one eruption of Old Faithful and never went further back into the geyser basin where the more interesting geysers lay. The kids had had their fill of geysers, so we headed off to new adventures.