The penultimate leg of my Route 20 journey was from Yellowstone to Boise, Idaho.
Yellowstone National Park, while mostly in Wyoming, spills over a tiny bit into Montana. This is the sign for Montana while still in the park:
Route 20 only cuts through about ten-fifteen miles of Montana that protrudes south, including mainly just the town of West Yellowstone, MT, so I didn’t get to see much of the state. Here is the more traditional Montana welcome sign:
Very shortly thereafter, I was entering Idaho:
Route 20 goes through a portion of the Idaho National Laboratory, much of which is top secret.
One section I was allowed into was a museum about the first ever nuclear power plant, the Experimental Breeder Reactor I (EBR-I):
EBR-I proved that it was possible to generate electricity from nuclear power, first by powering a string of light bulbs, then by generating enough to power the whole building. It never powered a whole city or anything that large, it was (as it says in its name) experimental, not built for large-scale practical use.
The other major accomplishment of EBR-I was that it bred nuclear fuel. The process is explained in the diagram below. It took a sufficient quantity of Uranium-235, which is highly radioactive, to sustain a chain reaction. Extra neutrons from the reaction combined with the more-stable (and thus less-useful as fuel, but also more common) U-238, which then became the more-useful Plutonium-239.
In the nearby town of Arco, ID, I ate an Atomic Burger at Pickle’s Place. It had sauteed mushrooms and onions on top.
Not far from there, Route 20 goes by the Craters of the Moon National Monument. I guess the difference between a National Monument and a National Park is that the former is created by executive order of the president, while the latter takes an act of Congress. It is co-managed by the National Parks Service, and my National Parks pass still got me in there though!
Here is the region from a satellite photograph: you can see how different the black lava flow area looks, compared to the green and tan areas surrounding it.
Apparently, people in the 19th century believed the area looked like how the surface of the moon. However, the craters there are not caused by meteor impacts but by volcanic activity instead. I learned the difference between some different types of rocks formed by cooling lava.
These pictures were taken walking near North Cone, from which they had flowed several thousand years ago.
I took another walk, around the Devil’s Orchard.
An interesting phenomenon had occurred to the limber pine trees there. Parasitic mistletoe had attached to the branches, causing the tree to direct more of its resources there and overstimulating branch growth into what is known as “witch’s broom”:
I climbed Inferno Cone, which is quite steep. You can’t actually see the top in this photo:
At the top, you can see for miles. Here is the 360 degree view:
In Idaho, Route 20 is called the Peaks to Craters Scenic Byway.
Also in Idaho, significant portions of 20 follow Goodale’s Cutoff from the Oregon Trail, which many settlers traveled in the 19th century.
More pictures from today can be found here.