The American West Part 5: Yellowstone National Park

The geothermal areas of Yellowstone include several geyser basins as well as other features like hot springs, mud pots and fumaroles. It is the place with the highest concentration of active geysers in the world because of its location in an ancient caldera.

The most famous of the geysers is Old Faithful first named in 1870. Eruptions can shoot boiling water to an average height of 145 feet (32 to 56 m) lasting from 1.5 to 5 minutes.

Over the years, the length of the interval has increased. With a margin of error of 10 minutes, Old Faithful will erupt 65 minutes after an eruption lasting less than 2.5 minutes or 91 minutes after an eruption lasting more than 2.5 minutes.

But for most of the time gentle wisps of steam leave one unsuspecting of what is to come.

The various geyser basins are located where rainwater and snowmelt can percolate into the ground, get indirectly superheated by the underlying Yellowstone Hotspot, and then erupt at the surface.

At Black Sand Basin when Spouter Geyser began erupting, the run-off created a dark pool with bright shifting colours in the sunlight. The pool is now known as Opalescent Pool but on this cold and dull morning it looked a sinister place with the dead, mist shrouded, skeletal trees in the background.

At other spots in Black Sand Basin scaldingly hot water bubbles out of the ground creating quite a fog on a chilly late autumn morning.

Firehole River, Biscuit Basin.

Not far away roaring sounds like that of some ancient steam ehgine, filled the air. Fumaroles issued from these hell holes.

In the northwest corner of the park there is a large hot spring complex called Mammoth Hot Springs. This is a large hill of travertine that has been created over thousands of years as hot water from the spring cooled and deposited calcium carbonate.

Moving eastwards across the Blacktail Deer Plateau we came to Tower Fall. Located in the NE of the Park on Tower Creek, about 1000 yards upstream from the creek's confluence with the Yellowstone River. The  fall drops 132 feet and is named after the rock pinnacles that you can see above the fall.

Carrying on southwards over the Dunraven Pass (8859 ft) on the caldera rim, we drove along the South Rim Drive of the Yellowstone River and walked out to Artist Point. Looking back we could see Lower Yellowstone Falls.
















At 308 feet high, they are almost twice as high as Niagara but very much narrower. It is here that the Yellowstone River drops over a 590,000 year old lava flow. The Lower Falls of the Yellowstone is the largest volume waterfall in the Rocky Mountains.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Because of the lateness of the season our original hotel was closed and we had been transferred to the Old Faithful Inn overlooking the famous geyser – a real bonus and an experience not to have been missed.

The original part was built during the winter of 1903-1904, largely using local materials including lodgepole pine, from which the bark was later removed, and rhyolite stone. When the Old Faithful Inn first opened in the spring of 1904, it boasted electric lights and steam heat.

The interior of the lobby contains four stories of balconies, but only the bottom two are open to the public due to earthquake damage in 1959. The balconies made a wonderful place to sit with a drink before going to dinner.

The dining room. The structure is probably the largest log building in the world.

Dead trees in an area of intense deposition of calcium carbonate 

The hot water that feeds Mammoth comes from a fault that runs underground through limestone. Algae living in the warm pools have tinted the travertine shades of brown, orange, red, and green.

Mammoth Hot Springs is the largest known carbonate-depositing spring in the world. The terraces have been deposited by the spring over many years but, due to recent minor earthquake activity, the spring vent has shifted, rendering some of the terraces dry.