Yellowstone National Park
Many million years ago, a gigantic volcanic eruption occurred and created a cauldron like area filled with thermal activities which is now Yellowstone.
Geysers are overheated underground water which are ejected from the underground caverns at various time intervals.
Hot springs are continues flows of heated underground water to the surface.
Mud-pots are heated mud and water mixture.
Most of northwestern Wyoming is taken up by Yellowstone. The national park road within Yellowstone formed a figure 8 loop. There are three entrances, South, West and North.
The altitude is very high averaging 6000 to 8000 ft. The air is so clear and there are no light pollution in the area. I was able to see the milky way at night. It was a wonderful sight to see.
In 1988 a fire swept through over 1/3 of Yellowstone and burned most of the trees in the area. You can see standing remains of pine trees burned in the 1988 fire mixed with new trees grown after the fire.
While inside Yellowstone, most of the points of interests are accessible by boardwalks. The earth crust may be thin or soft in the thermal areas. The spring and pools can be hot. Temperatures vary from place to place and from time to time. Some of them are acidic or contains sulphur. Geyser eruptions are unpredictable. Some top soil near the pools have microbe growth.
Old Faithful Geyser
Erupts at regular intervals. Beneath the surface cone is an underground chamber filled with water and steam heated by earth heat. The chamber is slowly filled up with underground water and slowly heated into steam. Pressure builds up until the geyser erupts and water and steam are ejected into the air over 100 ft high. This geyser erupts approximately every 1 hr 40 min and is believed to be the most regular on earth.
Mammoth Hot Spring and Minerva Terrace
Minerva Spring has wide range of bright colors and ornate travertine formations.