Every morning, when I walk the dogs out to the ridge overlooking our little corner of the lake, I can see steam rising from the West Thumb Geyser basin. Yesterday morning, I drove over there to walk around and take some pictures. West Thumb is a caldera within the caldera. A more recent eruption created it from within the giant caldera that holds Yellowstone Lake. While you won’t actually see geysers of the Old Faithful variety here, you will see boiling springs of azure blue (indicating the hottest of the pools) and steaming colorful paint pots with micro-organisms providing oranges, ochres, browns, and greens that steam away from the springs and into the lake.
And wildflowers. There were different wildflowers here than at our campsite, only two miles away. Harebells in abundance around the hydrothermal feature named Bluebell.
The place was thick with tourists, taking pictures of themselves with steaming geothermal stuff as the backdrop. There was a Ranger Interpreter out, leading a group from feature to feature, and teaching some geology as he went. I even learned one or two things by eavesdropping on the lesson. I learned, for instance, that you could gauge the temperature of the spring by the color. Blue is the hottest — over 163º. No micro-organism survives that high a temperature, so the only color you see in these pools is from the light being refracted by the water (similar to the water droplets that refract the light of the sun and produce blue sky).