Thermal Features in Yellowstone National Park

Wall Pool

This pool isn't clear like most others, it is a milky blue color. The shape and appearance of the pool changes depending on how high the water is. If the water is lower, there is a 6 inch high wall on the far side, if it is higher then the pool is larger, coming several feet towards the front of the picture. You can see scum line of orange bacteria towards the front left which shows how large this pool can get.
Date: July 14, 2019
Location: Biscuit Basin, Yellowstone National Park, WY