YELLOWSTONE NATIONAL PARK - The trek through fluffy snow and near-zero temperatures was like walking through a memory.
Exactly 10 years earlier, wolf biologists, politicians and others had hiked the same trail through two feet of snow, winding along a nearly frozen creek, through a ravine, and finally to a 1-acre pen tucked against a hillside above Lamar Valley.
They carried steel crates that contained young wolves from Canada that would be the foundation of Yellowstone's returning population.
On Wednesday morning, about 25 people retraced the route on skis and snowshoes until they reached the Rose Creek pen, a roughly circular enclosure built from tall chain-link panels and topped with an overhang bending inward to prevent any wolf from climbing out.
For Doug Smith, Yellowstone's top wolf biologist, returning to the Rose Creek pen brought a rush of powerful memories of Jan. 12 and 13, 1995 - the night the first wolves were released from their crates and into the acclimation pens.
Before the doors of the crates were opened - there were delays because of a federal legal challenge - Smith spent time feeding the wolves and watching them closely and forming indelible images in his mind.
Love them or hate them, wolves are nearly impossible to ignore.
"They have this presence," Smith said. Some people call it magic."
Smith and others reflected Wednesday on the first decade of Yellowstone's wolf reintroduction program, which has changed the history and natural order of the park and has become one of the most talked-about wildlife efforts in generations.
"The whole world is watching Yellowstone wolves," Smith said.
The 31 wolves brought to the park in 1995 and 1996 are all dead now, but their descendants now number about 170.
The population grew by 50 percent annually in the early years, tapered to about 10 percent a year and, for the first time last year, showed a decline. Smith said the Yellowstone wolf population has likely reached its zenith and may be entering a period where it stabilizes and then drops slightly for years to come.
"We think this is a significant point biologically for the wolves," Smith said.
Despite sub-zero temperatures at dawn Wednesday, wolf enthusiasts met in Lamar Valley hoping to catch a glimpse of the resident Druid pack.
There were few wolves to be seen - one observer said they had been staying close to the trees in recent days - but no shortage of enthusiasm. After a 50-minute hike up to the Rose Creek pen, which was used to hold wolves while they got used being in Yellowstone, they gathered to hear stories from those who were there 10 years ago.
In 1995, the pen held members of the Rose Creek pack for more than two months. The pen housed the Druid pack the following year.
Mark Johnson, who worked as a wildlife veterinarian during reintroduction, said he vividly remembered wolf No. 10, a big wolf who, unlike the others, wasn't scared to look the wolf biologists in the eye and follow them around the pen.
"He just had this confidence," Johnson said.
No. 10 also took to circling the pen eagerly. He was killed illegally later that year near Red Lodge, but not before he and his mate had pups. The female and the pups were brought back to the Rose Creek pen briefly.
Most of the pups stayed put except for one, which picked up No. 10's habit of circling the pen. Some speculate that pup was No. 21, which later became the alpha of the Druid pack and one of Yellowstone's most famous wolves.
Mike Phillips, who was Yellowstone's top wolf biologist in 1995, said he remembered the political pressure not to keep the wolves in the acclimation pens for too long. Some worried that extra time would allow the judge's decision allowing the release of the wolves to be reversed. Phillips and others, though, fought to keep them in the acclimation pens for the time recommended by other scientists and not let politics dictate when they were released.
"It was continuously important that we maintained what science told us," said Phillips, who now works for the Turner Endangered Species Fund.
Looking back, Phillips tried to pinpoint the most important moment during the reintroduction. In his mind, it wasn't the first wolf print in the snow or the first time wolves brought down an elk.
It was, he said, when wolves were released and didn't immediately bolt out of Yellowstone, as some had feared.
"The fact that they didn't go anywhere was the most important," Phillips said.
Norm Bishop, a park interpreter during reintroduction, remembered talking with a group of touring students 12 days after the first wolves arrived. He was struck that he no longer had to hedge his speech with "if wolves are reintroduced" and with speculation about what might happen.
"It dawned on me that it was no longer conditional," Bishop said, choking up with emotion. "Wolves were here."
Although the next 10 years brought plenty of controversy - including outrage from some about the effect of wolves on livestock and game animals - wolves have also become the most popular animal to view in Yellowstone.
The return of the wolf - a notion proposed by conservationist Aldo Leopold back in 1944 - has restored the top suite of native predators and also is restructuring the park's ecosystem, Smith said.
For wolf enthusiasts, that's a testament to the importance of national policies protecting endangered species.
"The success of wolf restoration in the Northern Rockies reaffirms the value of the Endangered Species Act as a safety net for wildlife," said Jon Schwedler of the Predator Conservation Alliance. There are plenty of challenges ahead, he said, "but if wolves can be recovered with the Endangered Species Act, it's a good bet any species can."
