GRAND PRISMATIC SPRING
The largest hot spring in the United States and third largest in the world is here in Yellowstone. It is located in the Midway Geyser Basin, which is 22mi (35km) from the west entrance. The beautiful colors of the spring are so vibrant. It has a temperature of 160°F (70°C) and not as hot as the other hot springs I've seen in Yellowstone. Due to the steam, I was unable to see the striking colors of the spring. I went around sunset time.
EXCELSIOR GEYSER POOL
Before it was a hot spring, this was an active geyser that erupted frequently reaching as high as 100ft (30m) up. Due to its inactivity, it is now a hot spring with a temperature of 192°F (88°C). This is one of my favorite hot springs in Yellowstone because of the clear turquoise water.
Midway Geyser Basin
Geothermal Spots (Map)