The activity at the thermal features of Yellowstone National Park varies day to today with both the above ground and the underground weather. This was our second stop at Mud Volcano, and it was much more active this day than the other, with huge plumes of steam. These are not geysers. They do not erupt. The output of super-heated water and steam is pretty constant. It is called a mud volcano because the water mixes with clay and emerges as a super hot slurry, with the consistency of heavy cream, and a smooth mud grey color. The close up of the plume is with the Sony a6700 and Tamron 50-400 Di iii zoom at 75mm, in Program mode, and the two other shots are from closer with the Sony a5100 and Sony E 10-18 f4 wide zoom at 15mm equivalent, and Superior Auto with the Landscape Scene Mode selected. Processed in Photomator.