Yellowstone is iconic in its own right, with its geothermal wonders and awe-inspiring landscapes. Within Yellowstone, there are few spots as iconic as Grand Prismatic Spring. On this particular summer day, we took a hike on the boardwalk to the spring. Stunningly, when we reached the spring, the sky matched the ground: cirrus clouds high in the sky mirrored the geothermally-formed lines on the ground, and puffy cumulus clouds lower in the sky matched the steam rising from the spring. I could probably return to Grand Prismatic 100s of times and never have quite these same unique conditions.