I forgot to mention that yesterday, as we entered Yellowstone, we saw a number of people pulled off the road with their binoculars and short-range telescopes out. A nice lady let us use hers, and through it we saw a mountain goat making its way across the sheer rock face.

Breakfast, not a usual meal for us on this particular trip, was necessary given the desolation we were to traverse. I had a delightful dish known as breakfast pasta, which consisted of cheese ravioli in a jalapeño sauce (with sautéed bacon, tomatoes, and other traditional omelet items), covered in a fried egg.

The one hilarity of this meal was in our bill (something in which few people can find humor). There was no charge for any of the food, and upon closer inspection realized that the meals on the ticket were not the meals we had eaten. My mom attempted to wave down our waitress to no avail and eventually had to track her down in order to straighten it out.

Between Boise and Idaho Falls are two routes nearly identical in speed: I-84, which curved south through the major cities, and US-20, which goes a little further north. Two years ago, we visited Craters of the Moon, but were unable to go very deep into the lava tube caves due to our flashlights burning out. This time, we vowed to return and conquer caves that we had left unexplored.

Because we entered from the east this time around, we first went through the Idaho National Laboratory, home of experimental research—some highly classified, no doubt—and the site of the first functioning nuclear power plant: Experimental Breeder Reactor I, shortened to EBR-I.

In December of 1951, the EBR-I facility was the first nuclear plant in history to produce enough electricity to produce a usable amount of electricity when it powered four light bulbs not too much larger than the kind used today. Its purpose, however, was not in the production of electricity on a large scale but rather to see if a "breeder" reactor was as reasonable as the theoretical models had predicted. True to form, the reactor "bred" plutonium as it consumed uranium, a process that could be refined and used until the reactor used up nearly 100% of the energy potential from a single rod.

EBR-I was deactivated in 1964 by LBJ, and was opened to the public in the 1970s between Memorial and Labor Days. We had been unable to see the site two years ago and stopped in for a self-guided tour.

The building is truly in the middle of nowhere, although it could be seen from US-20 from a long distance. Housed in a squat and unassuming tan building in the middle of the desert, the EBR-I site contains all the trappings of the mid-50s and early 60s; the beginning of the tour is set up like a family living room from the '50s and the bathrooms don't look to have undergone any serious upgrades since then either (although they have, thankfully, been cleaned).

The equipment is massive and industrial, full of thick metal walls and pipes of epic proportion. The upper level had a control room straight out of one of the early Bond films, and from there we could walk out onto the reactor and peer down into where the reaction actually took place. Above the hole is now a layer of thick leaded glass and a warning not to go in because of leftover radiation.

After helping a chemical engineer from the Netherlands get a proper picture of himself in the control room, we went past the site of the first lightbulbs. The originals have since been removed (one was on display on the ground floor), but in their place hang a series of identical bulbs, which put out an absolutely blinding amount of light. Nearby, a complex of white tubes easily a foot across at their smallest point once housed the coolant: a sodium-potassium alloy known as NaK.

The ground floor featured a "farm" of spent fuel rods which went deep into the floor. Behind it was a massive contraption: a metal "manipulator" used to scrape off detritus from spent fuel cells, all while shielding its operator with about a yard of concrete and almost two dozen layers of immensely thick leaded glass, which obscured and darkened what lay beyond it.

We also learned about EBR-I's successor, EBR-II. EBR-II was used until the mid-1990s and was proven to shut itself off under conditions worse than those that caused the famous meltdowns of history. The Chernobyl disaster left the public with a distaste for nuclear power that could not be assuaged by the scientists who rushed to assure the public of the EBR-II's safety.

Outside the EBR-I facility are two large reactors that were once used as prototypes for nuclear-powered airplanes. The project didn't get off the ground (pun intended) and was sacked after a billion dollars went nowhere towards practical nuclear air travel.

A return to Craters of the Moon was next. We went through the town of Arco (the first town to ever be powered solely by nuclear energy) and kept on towards the park.

Having been to the park before, we knew the routine, and quickly got a pass to go into the caves from the visitor center. While we've seen it in the past, the rocky black terrain is still as eerie as ever. I continue to be amazed at the diversity of wildlife in the park; flowers could sprout from the tiniest slivers in the dry rocks.

We hit the three hikes in the park worth doing before the caves: Devil's Orchard, Inferno Cone, and the small volcanoes known as Spatter Cones. (The second one we went into had snow at the bottom.) The Inferno Cone—not much more at a glance than a huge pile of black gravel—was a difficult uphill climb at the already mile-high altitude, but the views at the top were as stunning as I'd remembered—except better, because there were no other people at the summit.

But the reason we returned was underground. We packed our flashlights and water bottles in a backpack on my back and headed out onto the trail into the lava flows.

We first arrived at Boy Scout Cave, which soon became nearly impassible, for there had been a significant cave-in since we had last been there—even since our pamphlets had been printed. Slightly deterred, we knew there was one other cave to attempt: Beauty Cave.

Beauty Cave did not disappoint. We carefully climbed down the black rocks to the flat cave floor and shined our flashlights into the large cave. Little by little, we made our way to the back wall. Clear and slick ice formations surrounded the few hunks of rock on the cave floor, and we could see where the unstable rocks had had previous cave-in activity.

With something new accomplished, we went on to the largest cave of all: Indian Cave. After we went through the long, wide, and tall route that we'd gone through last time—one that required extensive climbing over rock piles caused by old cave-ins, we looped back around to the front. But Indian Cave doesn't just go one way; it goes no less than three directions once you descend into it. The leftmost path is the one we'd already traveled and one of the right ones dead-ended ... but the third, almost 180 degrees from the entrance steps, is the path less traveled by humanity. It was shorter but also required some significant rock pile climbing.

After this, we went back to the car, passing an eclectic group of people that ended with a man with long hair and a voice that said "wassuuuuup" in a way that was so laid-back as to be barely understandable. My dad said "I bet that's a drummer for some band." Sure enough, when we got back to the car, we saw a van emblazoned with "Sol Seed." Upon closer inspection, it was a band. Later research revealed that their fusion style hails from Eugene, Oregon.

Dad's hunger was ever-increasing and he began talking of spaghetti. According to him, the word "spaghetti" became stuck in his head like a catchy melody. We stopped at a rest area on US-20 outside of the park, which was uneventful except for the fact that Dad was simply convinced that, of the few people there, the teenage girls all had crushes on me.

The road to Mountain Home went down. The nearly 90º turns—the really bad ones—went unmarked while the easy ones—the ones you could conceivably go the 65-MPH speed limit on—were marked extensively. Add a setting sun reflecting off a bug-splattered windshield and truck drivers going 80, and it made for a nasty experience.

Mountain Home was the same as we'd remembered. We kept on the road to Smoky Mountain Pizzeria and Grill, a place where we'd eaten when we'd spent the night in Mountain Home two years ago. We sat in the same booth as last time, and I got the same thing: the black and blue burger, which had Cajun seasonings, blue cheese, and deep-fried onion straws (as well as lettuce and tomato) on a bun toasted enough to hold together under such a weight. The garlic parmesan fries were delicious. My mom got the "French Dip" sandwich, which had sliced beef, red onions, and cheese on French bread. The latter part of the name was the near-bucket of au jus gravy also on the plate. My dad got a personal supreme pizza.

We nearly beat the sunset to Boise, but we failed in that and entered road construction where you couldn't possibly know what lane you were supposed to be in or which lanes had been closed. Eventually we made our way across the city and to the suburb of Meridian, where it felt very good to crash.

Tomorrow: we drive to Bend, Oregon.