by Rick Lamplugh
July 22, 2015
We stand at the Mary Mountain trailhead and peer into early morning fog. Mary, Leo, and I expect to encounter bison on this trail. We would like a bit more advance warning than fog allows, but we decide to proceed slowly. Just minutes later we rejoice as the fog starts drifting away. We stop and take in a brilliant blue sky through an opening overhead. In the distance to the south, a thermal area near the Crater Hills begins to reveal itself, columns of hot mist mixing with fading fog.
Between us and the thermal area, a bison grazes on the lush grass, speckled with colorful wildflowers, that covers the broad floor of Yellowstone’s Hayden Valley. This bison banquet is irrigated by countless rivulets trickling from the slopes to the north. The rivulets will find their way to Alum Creek, flowing wide and serpentine through the middle of the valley. Along the way they cut the trail and create marshy bogs that boreal toads hop in and Leo and I sink in, sometimes halfway to our knees. Somehow, Mary stays dry.
As we make our wet way, I spot on a rise ahead a lone bull bison, one side of his head lit by morning sun, his eyes locked on us as we pass below. He stands like a guard at a gateway. A short time later we detour around two bison loafing on the trail. (I’m not calling them lazy; loafing is a step in their digestive process.) Moments later we make a wide, wet, bushwhack around two more bulls. When we encounter yet another bull blocking the trail, Mary dubs this hike a bison slalom.
We crest a low rise that is dry, covered with sage, and devoid of bison. From our vantage we watch as, across the valley, a big bull makes his way toward a smaller cow with a yearling in tow. When the bull starts running, the cow and calf take off. The bull sprints, closes the gap, and separates the cow and yearling. He pivots—a surpassingly agile move—and forces the yearling to run away from the mom. It is mid-July, the rut approaches, and the bull has sent a clear message: Beat it, Shorty. I’ve got business with your mother.
As the bull, cow, and yearling speed toward the Grand Loop, I feel a mixture of admiration and awe for these beautiful creatures that Mary and I had so much time to observe while we spent three winters living and volunteering at the Lamar Buffalo Ranch. We watched them stand, facing a storm, whipped by wind and showered by snow in a race between starvation and spring. Every time they trudged forward, we knew they were using another pinch of energy that would not be replaced by the dried grasses they struggled to uncover. During our second winter at the ranch, I began to wonder just how this animal evolved to survive such harsh conditions. What was the story behind bison? What I found amazed me.
The ancestors of Yellowstone’s bison lived in southern Asia two to three million years ago. Over the course of a million or so years they grazed northward, according to Harold Picton in Buffalo Natural History and Conservation.
No one was around to record that long migration, but I can imagine capturing it with time lapse photography taken over, say, 500,000 years. Playing that film back, we would watch that animal adapt. We would see its head grow larger and more massive, better suited for bulldozing snow to reach grasses that provided as much nutrition as eating an empty cereal box. As the head grew heavier, a shoulder hump would appear, evidence of the muscle and bone required to maneuver that mass. We would see the animal’s hair grow longer, providing better protection against colder northern temperatures.
And there would be adaptations we couldn’t see. Beneath the lengthening hair, the hide would thicken, yet more insulation. The animal would improve at producing and storing fat, the secret ingredient for surviving long winters without nutritious grasses.
At the end of that time lapse photography, if we stood an original animal next to the evolved one, we would see differences so great that we would need a name for the “new” animal. We could call it the Asian bison.
That Asian bison migrated so far north that they reached the area now called Siberia and ran into the Bering Strait, a body of water too wide to swim. Stopped in their tracks, they settled into northern living.
Then, around 200,000 years ago, the bison felt the icy touch of the first of many climate changes. Over tens of thousands of cold years, the ice in the Bering Strait no longer melted. As year-round ice formed and sea level fell, a bridge of land slowly appeared, connecting Siberia with what we now call Alaska. On that land bridge, grass seed, freed from icy water and exposed to warm sun, sprouted, grew, and created an inviting pasture. Following their noses, Asian bison grazed this thousand-mile bridge to North America.
Over time, temperatures rose, year-round ice melted, and the rising waters of the Bering Strait swallowed the land bridge. The bison that had crossed from Asia could not return, but they could do what bison do best: graze, reproduce, adapt. After tens of thousands of years, the Asian bison evolved into the North American bison.
By the time European settlers arrived in the New World, 25 to 30 million bison roamed the Great Plains. But not for long. The hordes of humans rumbling westward in wagon trains, searching for land and a brighter future did not have refrigeration but did have to eat. And there, grazing within easy rifle range, stood mobs of meat. The killing frenzy began. Sport hunters with no intention of eating their prey slaughtered thousands more. Fashion even played a part: the chilly Little Ice Age in the mid-1800s created a hot market for millions of warm buffalo hides. Then came the calvary, eradicating bison as a way of eliminating the Plains Indians.
But the straw that broke the bison’s back was America’s growing industrial might. Bison were killed to feed the thousands of workers laying the tracks for the new transcontinental railroad that would unite this country. A good commercial hunter could kill a hundred animals in one day and not stampede the herd. Also in bigh demand were bison hides after a new tanning technique made it possible to use them to make the belts that drove the machines of the Second Industrial Revolution.
After fifty years of killing for food, sport, ethnic cleansing, profit, or progress only about 1,000 bison remained on the Great Plains. Yellowstone’s herd had been decimated as well. Poaching in the park was rampant and profitable: A bison head could fetch $300, the equivalent of about $6,000 today. Protecting the remaining bison challenged the U.S. Army, then responsible for the park. By 1900, only two dozen or so bison survived in Yellowstone’s remote Pelican Valley.
The government stepped in: Congress appropriated money to rebuild the herd: $15,000, equivalent to about $400,000 today. The project imported to Mammoth eighteen cows from Howard Eaton in northwest Montana and three bulls from Texas.
Within a few years, this so-called captive herd outgrew the Mammoth pens and was moved to the Lamar Valley. For about fifty years, ranch hands raised bison at the Lamar Buffalo Ranch in the same way that cattle are raised. In 1936, 71 bison were transported from the Lamar Valley to form the Mary Mountain herd. After one of the first and most successful wildlife restorations in the world, Yellowstone’s two herds now total about 4,900 head. There are 3,500 roaming the Lamar Valley. The other 1,400 call Hayden Valley and the Old Faithful area home.
As Leo, Mary, and I start the return trip to the Mary Mountain trailhead, the wind picks up, bringing the grunts and groans of a herd of bison grazing to the west. Enjoying the conversation of these descendants of the animals moved here almost 80 years ago, I smile. I’m thankful that Yellowstone became, in the words of Robert Steelquist, a biological ark for bison, which gives us the chance to admire—and avoid—these resilient survivors.
Rick Lamplugh lives near Yellowstone's north gate and is the author of the Amazon Bestseller In the Temple of Wolves: A Winter’s Immersion in Wild Yellowstone. Available as eBook or paperback. Or as a signed copy from the author.