One of the most popular sites to visit in Yellowstone is the Grand Prismatic Spring. It's popular among people and also for bears as recent visitors at the park discovered when they saw a huge grizzly walking down the boardwalk.
I love Yellowstone. Within Yellowstone, I love the Grand Prismatic Spring. That's why I was happy to actually learn something I didn't already know about it. A new video explains why it has all of its pretty colors.