Over the past week, as each thread of our ordinary existence unravels and travel feels like something we used to do, I’ve been holding tight to a single mental image. The deep brown gaze of a caribou calf as it passed inches from my face. The whites of its eyes as it glanced at me in surprise. The animal’s fear of the unknown dwarfed by its clarity of purpose.

On St. Patrick’s Day, 2012, my husband and I had set out on a 4,000-mile, human-powered journey from Bellingham, Wash., in the Pacific Northwest to Kotzebue, Alaska, far above the Arctic Circle. For nearly six months, traveling by rowboat, ski, packraft, foot and canoe, we’d made our way across some of the most remote landscapes on Earth.

In the last days of our trip, we were canoeing down the swollen Noatak River in the Brooks Range of northern Alaska. Winter had arrived early that year and we paddled through the damp chill of rain turning to snow. Bundled and shivering, we never imagined we’d find ourselves hunkered down on a riverbank surrounded by caribou, our breath mingling with theirs.

But late one afternoon, as we rounded a bend in the river, I noticed what looked like a branch floating downstream. And then another. By the time we realized we weren’t seeing branches, but antlers, two caribou had landed on the far shore. They pranced and shimmied, water flying in beads off their coats. Waiting at the river’s edge were dozens more animals, poised to cross. We pulled our canoe out at the next eddy and stopped to watch. When the last of the animals had finished their swim, we hiked along the brushy bank to find the trail they’d followed to the river. At our feet was a crisscross of tracks, pressed freshly into the soft mud.

At first, everything was still. Then a wave of sound approached like a squall across the water and we crouched down to hide in the bushes. We felt the wave of energy before we saw the first animals, funneling down the hillside toward us. Suddenly we were embedded in the migration of the Western Arctic Caribou Herd. So close I could have reached out and touched their backs, the animals passed in single file on the path beside us. There were dozens of caribou, then hundreds, and soon we lost count. Breath steamy in the cool air, tendons in their legs clicking audibly, black noses moist and shiny, the urgency of their motion was palpable. They stopped only briefly to gather at the riverbank before crossing.

In magazine spreads and documentary footage, caribou migrations look perfectly choreographed. From the air, tens of thousands of animals move synchronously as they dance across the tundra in sinuous waves. On the ground, backstage with the dancers, I discovered a different scene entirely. Instead of an orderly procession, the migration felt jumbled and jostling, anarchic and frenzied. Picture a schoolyard of kindergartners lining up from recess, limbs flailing, bodies in motion, all jockeying for position.

This was made worse by the fact that the river crossing had formed a bottleneck: Each caribou had to decide whether to leap from a 6-foot bank into the swirling gray water below or to continue down the trail to another entry. In the moments of indecision, it was almost always a cow and calf that first took the plunge. The calves held tightly to their mothers’ sides, each pair exchanging quiet grunts as they splashed in the swift current. They were the ones with the most at stake; they were also the ones that couldn’t afford to delay. Still, they hesitated and stumbled, sometimes stepping forward only to jolt back a moment later, letting another caribou pass. I hadn’t ever imagined such disorder among these highly social animals, such chaos in their movements.

But the longer I sat and watched, the more I began to notice the nuances of the herd’s dynamics. Each animal’s actions were driven by something larger than itself. Behind the chaos was the collective need to move. And no matter how frantic the motion felt, no matter how many more animals came down from the hills and joined the bottleneck of the river crossing, I never saw a single shove. No caribou were pushed into the water or trampled against the bushes. It was as though a safety bubble hovered around each animal, with an unspoken, absolutist rule shared among the herd: Do not harm thy neighbor.

IN THE nearly six months since we’d been away, the rawness of the landscape had distilled our needs to their most basic forms: food, shelter and love. Instead of juggling emails or worrying over the deadlines I’d missed, I scanned for bears on the horizon and anchored my tent against a building storm. I felt for the tenor of the wind against my cheek and probed the strength of the snow like checking for a pulse. I read the tundra as if by Braille, always in search of solid footing. As we’d traced the curvature of the Earth with paddle strokes and footsteps, the world grew and shrunk at once.

By most definitions, we’d been extremely isolated. For 176 days, our close contact had been solely with each other, with whom everything, from sleeping quarters to cookpot, was shared. But we’d never really felt alone. On glaciated peaks and in mossy coves, over steep mountain passes and through raging spring storms, we shared the company of winged and four-legged companions, all on their own remarkable, unsung journeys.

After launching hand-built rowboats in a hailstorm, after facing mosquitoes and avalanches and a predatory bear, I had learned to focus on one thing: the now. Just days before we’d met the caribou, we’d waited in a rainstorm on a riverbank for a food resupply that didn’t come. We’d lain in our tent, shivering and scared, and wondered if we’d meet our end by this most slow and plodding of means. We discovered the limits of our bodies and then some. For almost five days, we survived on two crumbly granola bars, a few tablespoons of olive oil and a package of instant ramen. Impossible questions hung beside us in the already heavy sky. Had we asked too much of ourselves, and of the land? Was it really worth it in the end?

When the plane finally came to deliver our resupply, we ate until we were sick. As we paddled away the next morning, I wasn’t sure what lessons we had gained, except the fact of our own obvious and humbling mortality.

But on that rainy afternoon, in the collective energy of bodies in motion, hurtling themselves into the current of a cold Arctic river, grace abounded. For hundreds of miles we’d traveled in the shadow of caribou, trusting their wisdom to guide us over terrain that often felt impenetrable. By following their hoof prints and rutted tracks across the mountains, we’d learned that there was always a way forward.

When a caribou calf stopped to sniff me then skittered away to join the others, I realized I’d found what I was looking for. Faith in the unknown. Beauty when I least expected it. The visceral relief of bearing witness to something much larger than myself. After nearly starving on a riverbank, the delay in our food resupply felt serendipitous beyond belief.

LIKE ALL of us, I’m grasping for connection in a time of uncertainty. I hear the school bell ring down the street and listen reflexively for the children’s voices that don’t come. I stand 6 feet from my sister and feel the void stretch deep and aching between us. I hug my children close, because I still can. And then I shut my eyes and imagine the caribou bedded down in the snow, trusting the sun to rise and warm their backs, knowing that the night will pass.

We are not caribou. We don’t pound our hooves against the earth each spring and fall, in search of food and shelter. We can’t survive on frozen lichen and the warmth of our fur coats. Mosquitoes and wolves aren’t our greatest foes. The ordinary facts of our human lives do matter, and deeply. But even now, when I most want to believe in happy endings, I find myself turning toward the harshness of an Arctic river. In the wild eyes of a floundering calf separated from its mother, in the bleached white skull of last season’s casualty, I take solace in simply being present. The caribou remind me that we must reconcile the tenuousness of our existence with the preciousness of what we stand to lose.

In the end, perhaps we aren’t so different from the caribou crossing the river. As we struggle against the current, we’re buoyed by the fact that we’re not alone. We greet our neighbors on the screen, through windows, at distances that feel strained and unnatural, and exchange silent blessings, recognizing that for us, like for caribou, community is everything. We know that there is no one to save us except ourselves.

By gathering the courage to jump, waiting for the shock of the cold water to pass, and feeling the ripples of our individual choices, we begin to move as one. To survive together, we must be brave. We must be compassionate. We must learn when to step forward as leaders and when to step aside so others can pass safely. And during those moments when fear steals my breath, I will remember the steam rising from the backs of caribou, see the mothers plunging boldly into the cold water with their calves by their sides and let myself believe that we, too, can find our way.

Caroline Van Hemert is a wildlife biologist and the author of “The Sun Is a Compass,” which was released in paperback in February.