BOZEMAN, Mont. — The day the wolves arrived in Yellowstone National Park was busy. At least that’s how Norm Bishop remembers it.

The wolves came in aluminum crates on horse trailers Jan. 12, 1995. Passing through the gates, the Canadian-born carnivores were the first of their kind in the park in decades, other than the occasional rumor or random sighting.

Bishop, who was Yellowstone’s resource interpreter, had spent years giving public presentations about the science of wolf reintroduction. He would explain what the experts thought would happen if gray wolves were restored to the Yellowstone ecosystem. How they weren’t likely to injure people or devastate the livestock industry or eat every single elk.

How they were a missing piece of the ecosystem, and how things might change things if they returned.

Each time, he used that powerful two-letter word — “If wolves are reintroduced …” — because there was no guarantee this day would come.

Then it did. But there wasn’t time for him to marinate in the significance. There was work to do.

“For me, it was just kind of busy,” Bishop said.

His day began early. He went to Crystal Bench, east of Tower Junction in the northern part of the park. One of the park’s three acclimation pens was there. The wolves were to live in those pens until biologists believed they were ready for the wild.

After the truck convoy got through the park gate — where a crowd of wolf advocates, reporters and school children had gathered to watch — it headed east from Mammoth Hot Springs. Once it was close enough to the pen, it stopped and park staffers loaded six of the crates onto a mule-drawn sleigh. The sleigh carried the captive animals over the snow to Bishop and the others tasked with hauling the boxes to the pens.

It wasn’t easy — 100 pounds of wolf inside 100 or more pounds of metal. Four people per crate. They were as quiet as possible. So were the wolves, Bishop remembered, unaware of the fanfare of their journey.

He helped carry the second crate, which held the alpha male of what would become known as the Crystal Creek pack. Photos from that day mostly focused on the first crate — a good photo op for Interior Secretary Bruce Babbitt, who shared the load with Yellowstone superintendent Michael Finley and the U.S. Fish and Wildlife Service director Mollie Beattie.

In some of the images, Bishop can point to a glove or leg that belongs to him. But there’s one where he’s unmistakable. It hangs on the wall in his office. It shows him whispering in Babbitt’s ear, telling the secretary where the crate carrying the alpha female should go.

For a long time, wolves were viewed as a nuisance. Something to be killed, not preserved. People viewed them and other predators as dire threats to livestock and the wildlife species people liked better — like deer and elk.

The effort to get rid of wolves was successful in the Yellowstone region. While a small population held on in northwest Montana and Canadian wolves did OK, they were extirpated from the greater Yellowstone ecosystem. The last known pack was killed in 1926, though sightings of single wolves were occasionally reported after that.

Looking back on that era now, biologists and conservationists would view the park as incomplete. Bishop described it as a Bach concerto without the trumpets.

Crates being dropped off 25 years ago Sunday was the beginning of the return of the trumpets. Now, there are people old enough to drink and smoke and rent cars who have never lived in a world where the Yellowstone ecosystem didn’t have wolves.

Biologists and conservationists have seen it as a great success.

“It truly was and is a rebirth and recalibrating of what is the essence of Yellowstone,” said Finley, the former superintendent.

Doug Smith, the park’s top wolf biologist, was hired for the reintroduction and has spent the last two-and-a-half decades watching what came next.

He’s seen wolf numbers ebb and flow. The population peaked in 2004 at 174, but it’s since declined and stabilized. He said it has hovered around 100 in 10 packs since about 2008.

He’s seen the dire predictions propagated by opponents of reintroduction fall by the wayside. Among the wildest was the claim that wolves would hurt people. No one has even been bit by a wolf in Yellowstone.

He’s seen the ecological changes the wolves brought. Most prominent is the decline in elk. The population in the park’s northern range has dropped from roughly 20,000 to between 6,000 and 8,000.

That came to the chagrin of hunting outfitters north of the park, who can make money on big elk that cross the park’s border. But Smith and other biologists say that 20,000 elk was too many and that the park is healthier now. The park’s vegetation has benefited. Aspen and willows can grow taller without so much pressure from elk browsing for nutrition.

“Yellowstone is a better place with a fully intact carnivore guild,” Smith said.

Getting to that version of Yellowstone required about 20 years of preparation in the face of fierce opposition from people who thought the world was better without wolves.

John Varley, who was Yellowstone’s chief scientist through the 1980s and 1990s, oversaw much of that work. Because it was so controversial, he knew the park needed to take the time to explain how this could work without the sky falling. Some could never be convinced, but the case had to be made.

“You’ve got to get the public ready for this,” Varley said. “So that’s what we did.”

Bishop was a key player in that effort. As the park’s resource interpreter, his job was to explain science to people, to translate the intricacies of an immensely complex place. Wolves became a big part of his job, and he learned all he could about them. He wound up giving about 400 presentations around the country, making the case for bringing back the carnivore.

“He had kind of a road show,” Varley said.

Tall, thin and 87, Bishop lives north of Bozeman with his wife, Dorothy, in a modest house with an immodest view.

His office is full of books and documents he’s held onto over the years, many of them related to wolves. On a recent Friday, he showed off the parts of his collection he deems most relevant and launched into the story of wolves, like the road show never ended.

He talked about wolves living in Yellowstone long before it was a park, alongside the elk. He talked about 1926, the year the last wolf pack was killed. He talked about the early attempts to get traction for reintroduction, and how they foundered.

He listed the experts and scientists and bureaucrats who were crucial to the success of reintroduction. He’s still in touch with some of them.

And he described the success of reintroduction. How the predictions from the experts were pretty much right on, how the restoration led to a “quantum leap” in the world’s understanding of wolves through the hundreds of peer-reviewed papers examining their lives.

“When I say quantum leap, I’m not exaggerating a bit,” he said.

Soon nearly two hours had passed without anybody noticing but Dorothy, who poked her head into the office to let him know it was about lunchtime. He asked for a handful of grapes and continued.

Moments later, she reappeared with a wry smile and his order in a small white bowl.

“He’d rather talk wolf than eat,” she said.

Bishop came to Yellowstone after a couple of decades with the National Park Service as a naturalist and interpretive specialist in a few other parks, including Rocky Mountain, Death Valley and Mount Rainier. What he describes as a bureaucratic “fluke” brought him to Yellowstone in 1980.

He said the work he did to make the case for wolf restoration really began about seven years later, after the final Northern Rocky Mountain Wolf Recovery plan was signed. The document said it represented a “road map” to recovering the wolf population by establishing 10 breeding pairs in the recovery areas, which included northwest Montana, central Idaho and the greater Yellowstone ecosystem. What came next was a full environmental impact statement, which set the stage for the wolves to return.

As work on that document went on, Bishop traveled around, giving his talks. Milwaukee, Utah, Colorado — always with the word “if,” never proclaiming reintroduction to be a certainty.

It was starting to look like a certainty in 1994, with the finalization of the environmental impact statement and the hiring of the people who would make the reintroduction happen.

Mike Phillips was chosen to lead the project. He’d worked for the U.S. Fish and Wildlife Service in North Carolina and led the reintroduction of red wolves there. That meant he had experience bringing back a predator, making him an obvious candidate.

Or, as Phillips puts it: “There was one guy in the country that had so much wolf piss on him that he was the no-brainer choice.”

Smith was hired as the project biologist. It was his fourth wolf job. He came from Isle Royale National Park, where he’d been for 15 years.

The wolves that were brought to Yellowstone and central Idaho came from Canada. Phillips said the U.S. Fish and Wildlife Service took care of that part of the work, so he and Smith mostly stuck around Yellowstone in the days leading up to reintroduction, making the final preparations.

They made sure the acclimation pens were ready and stockpiled roadkill so they’d have something to feed the wolves. Unlike the wolves that went to Idaho, which were immediately released to the wild, the Yellowstone wolves were booked for a “soft release.” They’d live in the chain-link fenced pens until the biologists were confident the animals wouldn’t instinctually bolt for Canada.

Phillips said they planned well, which helped them out when the wolves arrived in a state of legal limbo. A legal challenge from the Farm Bureau federations of Idaho, Montana and Wyoming resulted in an order from a federal judge that barred their release from the crates, even into the pens.

They put the crates in the pens anyway, and then the top brass left the park for a press conference about the legal wrangling.

Smith stayed in the park. The hope was the judge would lift the order that day and that they could at least get the wolves out of their boxes. He ate dinner in a pickup and waited as day became night.

Word eventually came that the judge had lifted the order. Smith waited for Phillips and others to join him. Then they trekked to the pens in the dark to lift the sliding doors on the crates. Not all of the wolves came out immediately, but Smith could feel the gravity of it all.

“You’re walking on snowshoes at 2 a.m. in the morning,” Smith said. “You kind of just had this moment alone with the wolves in the dark, and history was being made.”

Bishop was not on the late-night trek, but he had helped carry two crates that day. Thinking back on it 25 years later, he wonders why the significance didn’t immediately overwhelm him. He doesn’t have much of an answer, other than that it was a busy day.

But he knows when it did finally hit him. Weeks later, when he was giving a wolf talk to a school group visiting the park. He started to make the same old qualification he’d been making for years: “If wolves are reintroduced … “

He stopped, realizing the preamble was no longer necessary.

“They were here,” he said. “It was done.”

A week after the first eight, another group of wolves arrived. A few months later, they left the acclimation pens and entered the wild.

A couple months after that, Bishop got his first wolf sighting. In the Lamar Valley, with Dorothy. Some wolves chasing around some elk, bringing down a couple of elk calves and fighting with the cows.

He left the Park Service but he never left the wolves. He taught wolf courses in the park for five years, totaling more than 50 of them. He stayed engaged in the science, following Smith’s Yellowstone Wolf Project closely and picking up just about every book that came out.

He looks at wolves every day now. Five paintings of them hang on the walls in the front room of his house. Another is in his office, opposite the photo of him telling the interior secretary what to do and the many awards he’s won for giving voice to the wolves.

There’s talk of reintroducing wolves to his home state of Colorado, a project Phillips has been involved in through his work at the Turner Endangered Species Fund. Bishop would love to see it happen. He talks about how there’s plenty of room and plenty of elk and how it seems the same people are coming out of the woodwork to oppose it.

You can see how a couple more hours could fly by and how he could forget about time and maybe even hunger. He’d rather talk wolf than eat.