Rainbow pools of bacteria at first did not seem like the first place to stop at Yellowstone, but it was close so we gave it a go. As we walked along the boardwalk through the steam and clouds we were not impressed. No rainbows here. Right before we got back in our car we saw another trail around the pools and went up a hill. We got to the top and then saw the yellow, orange, blue and green pools and the mist coming from them making it look like it was making rainbow clouds.