There are two high schools off of I-35 that are just about the same size. The first is 45 minutes out of downtown Oklahoma City, southbound—Noble High School. This year their enrollment is at 807 students. Ardmore High School, an hour and a half farther south on the interstate, is just a hair smaller at 802. Imagine, briefly, that one of these schools was all that was left. I don’t mean the only high school left in Oklahoma, or even in the United States. I mean the only collection of humans left on the planet. Imagine that, as the result of some apocalyptic scenario worthy of blockbuster YA, the students at either Noble or Ardmore became the full complement of us—the sole survivors and last representatives of our species. That would put humans right on pace with the critically endangered mountain gorillas of central Africa today.

“Freaking go-rillas!” were among the first words my wife and I exchanged when, late last year, we got confirmation of our impending move to Rwanda. Just to be upfront about how nerdy we are vis-à-vis wildlife watching, we once named a whole summer “The Summer of the Wood Duck” because it was our overriding goal to see and photograph one of those absurdly beautiful birds in their nesting trees (we did, and felt like winners). Trekking up to see the gorillas in Volcanoes National Park had been a fantasy of ours since learning that such a thing was even possible. A fantasy deserving of the name, considering how far out of reach it was geographically and financially. But our relocation to Kigali put us just over 100 kilometers away from some of the most charismatic and rare animals on the planet. Early this April, exactly a month after arriving in Rwanda, we visited them for the first time.

The drive up from the capital brought us over a rippling quilt of alternating greens—banana and climbing-bean and tea. The countryside here is dense with hills, and every vista offered just a little bit more than we could process; the world in massive miniature. Like if big hands took Oklahoma about the borders and pressed it inwards, so that it puckered, folded and compressed. You could fit nearly seven Rwandas inside the state, but a square mile in this small nation has almost 20 times more people than one over there. As such, nearly every scrap of land that isn’t covered by tarmac, dwelling, or water is given over to intense cultivation. We passed a few towns on our drive up, but they were small, open, and airy. We saw crowds nowhere, and people everywhere.

Our trek to the gorillas started early the next morning, at the ranger station by the base of the park. All of the family groups in Volcanoes are used to seeing us goofy color-draped primates by now, though many of them have only been habituated for research. This leaves 10 families open to tourists, each of them visited for no more than one hour a day. At the station we were divvied into groups of eight or fewer, based roughly on the guides’ estimation of our physical fitness, and the clearance of our vehicles—some of the families are higher in the mountains than others, some of the roads more gutted by rain. My wife and I were thrilled to land in the Susa group, one of the largest families in the park, originally habituated by Dian Fossey. They often sleep deeper in the woods, on the bamboo-covered slopes of Karisimbi—the hardest hike. Thank God for slimming pants.

I didn’t exactly expect a big, festooned entrance—some Jurassic-Park-style gate announcing our passage into the wild—but still I was a little surprised when our guide directed us to park at what looked like a small trading post. The farms, I realized, climbed right up the mountain. For the first hour and a half of our hike we scaled terraced fields of flowering Irish potato, saying “Good morning!” to a steadily growing entourage of children. Our guide, a former poacher, quizzed us on plants and told stories about growing up at the edge of the park. About sick gorillas crossing the boundary in search of eucalyptus to settle their stomachs. About an old silverback who could find and bypass snares. Finally we came to a low, stone and mortar wall, at which all cultivation stopped. This is the corner of the map, so very very tiny, where it would say “Here there be some Giants left.”

After a little under half an hour of tunneling through bamboo we encountered a pair of trackers. They had us drop our packs, and pointed the way to the gorillas. Clichés abound in writing about encounters with large animals in the wild. I have twice now typed sentences that contained the words “contact” and “kinship” and deleted them because they were so unforgivably shitty. Everything that you think is true about seeing a gorilla in the wild is true. We arrived at a little clearing, electrified and flabbergasted and repeating the words oh my God and oh my God, and a young gorilla, just five or six years old, walked right up to my wife, circling around her to get to what was apparently some superior bamboo. The silverback looked at us and grunted occasionally and seemed a little bored and sleepy and happy with his life, his family all around, a set of twins wrestling in the stinging nettles. Somebody said something stupid like: “They look so lifelike,” and everybody laughed, but quietly. An hour among them passes so very quickly. We returned the next day, somehow no more prepared than we’d been the first time, to visit the Titus family. It was a smaller troop, run by a silverback that had recently assumed the throne from his dying father. He had a son, just three weeks old, nursing, and never did the clicking of so many cameras sound less inauthentic. Our guide explained that babies at that age have about a 60 percent survival rate, and we decided that this one, briefly ours, would be just fine.

On the drive back to our house in Kigali, my wife and I tried to tally how many individuals we’d spotted in the two different families. It came to around 40, a number which delighted us, at first. Then we drove quietly for a while, the road dipping and rising. I think that we both realized at the same time that in just two hours we’d seen about five percent of the entire surviving population of mountain gorillas. I’m not a pessimist by nature. In June there will be a ceremony for the young ones. They will all get names, and one day their troops will carry those names.