The Fountain Paint Pots
The Fountain Paint Pots are a collection of mud pots, pools, and geysers several miles from Old Faithful. The orange area is a "bacteria mat" where bacteria - adapted to the very warm water - live and multiply.  A mud pot, upper left, can grow quite thick as the summer progresses. The amount of water available also determines their viscosity. Unfortunately, when we visited, Yellowstone had not had any rain for many weeks. Still this area was fascinating in its own way.