From the return of wildlife to the pressures of tourism and the climate crisis, Steven Fuller has seen it all in his nearly 50 years watching over America’s oldest national park

As “winterkeeper” at Yellowstone national park, Steven Fuller lives in a rustic cedar-shingled cottage, built in 1910, set on a hill a short walk from the majestic Grand Canyon of the Yellowstone.

On balmier days, with the windows open, he can hear the roar of the 308ft Lower Falls tumbling into the chasm. In autumn, he is treated to the sound of bugling bull elk in rut or, in the middle of night, the howls of wolves.

A key part of Fuller’s professional responsibility in winter, when deep snow and bone-chilling cold shuts down tourist operations for five months in the centre of Yellowstone, is removing snow from building rooftops to prevent them from collapsing under the weight of the load.

His solitary existence might seem idyllic, but when Fuller and his English wife, Angela, landed the winterkeeping assignment in 1973, there wasn’t a long line of competitors. He was the only applicant.

“Back then, being a winterkeeper at Canyon was considered a hardship post where the isolation was reputed to drive people crazy,” Fuller remembers, noting they had no phone or TV and the internet was decades away. In the evenings, they listened to BBC news broadcasts via shortwave radio.

“Then again, in those days, the world seemed a much bigger place, with fewer of us on the planet and such a thing as solitude wasn’t in short supply,” he adds.

Today, the proliferation of digital technology, which enables faster-paced park visitors to share a selfie on social media from the remotest mountain peaks, has made Yellowstone’s vastness feel smaller, he says.

The bittersweet lament comes as Yellowstone marks its 150th anniversary on 1 March as America’s first national park and one of the first in the world. For Fuller it coincides with his 49th year as Yellowstone winterkeeper, the longest anyone has held the post in the park’s history.

“Going back to the 19th century, winterkeepers tended to be basically backwoods good ol’ boys, and not necessarily with a high level of education,” retired Yellowstone park historian Lee Whittlesey says. “They were looked upon as refugees from civilisation, trying to get away by hiding out as hermits. Steve Fuller has done a lot to change that prosaic image, but he has his own Thoreauvian place as an anomaly in the 21st century.”

Fuller says the changes he has observed in Yellowstone have been profound. “It’s difficult sometimes to sort out the paradoxes,” he says.

Yellowstone is coping with record numbers of visitors and yet, Fuller notes, the park is in some ways wilder than when he arrived.

Grizzly bears, whose numbers in the park dipped to just 136 in the 1970s, have been rescued from a population freefall. Wolves, deliberately exterminated by park rangers in the 1920s, were brought back in the mid-1990s. And bison population, which numbered just 23 at one point in the late 19th century, is today at 5,000.

In 1973, the year Fuller arrived, there were slightly more than 2 million visits recorded in Yellowstone. Last year, Covid-19 set off a rush of people to the park and there were nearly 4.9 million – 800,000 more than in 2019, the year before the pandemic struck. This year, given the publicity for the park’s 150th anniversary, Yellowstone may surpass 5 million visitors.

Tourism brings millions of dollars in revenue to neighbouring communities and creates thousands of jobs but the growing numbers have come at a cost, says Fuller.

“Traffic congestion in summer is a lot worse – a lot. I experience it first-hand,” Fuller says. “I’m reluctant to go anywhere in the park during the day when I have free time. You might set out on a drive that would ordinarily take you 30 minutes, but the chances of getting stuck in traffic and taking three times as long are good.”

Most tourists stick to the roads and short trails, directly affecting only about 2% of the park’s 8,900 sq km (2.2m acres), notes Yellowstone superintendent Cam Sholly. Scenes of traffic gridlock and full carparks are real, but they create an inaccurate perception, Sholly says. Most of Yellowstone is sparse of people and the farther one wanders away from the asphalt, the more likely it is that wildlife outnumbers those on two legs.

The crowdless backcountry serves as an important refuge for wildlife, but this space is shrinking amid a development boom in the Rocky Mountain west. Sholly is also concerned about the climate crisis dramatically altering habitats for wildlife, and the growing threat of exotic plants overtaking native species that support the health of animals such as elk, deer, pronghorn and bison.

Fuller echoes Sholly’s worries. “We’ve had 20 below [fahrenheit] with more frequency, but not the deep cold stretches of minus 30, minus 40, sometimes 50 below that were a defining aspect of winter here,” Fuller says. “While weather swings are normal, the trend, overall, is in the direction of earlier spring meltoff.”

His perception is corroborated by scientific evidence. Over the last half century, the growing season (the time between the last freeze of spring and the first freeze of autumn) has increased by 30 days in the park’s valleys. Meanwhile, near Yellowstone’s north-east entrance, which has typically been colder than other parts of the park, scientists say there are 80 more days a year above freezing than in the 1960s. Such conditions mean the snowpack is melting during winter and leaving the mountains earlier in spring, which causes some rivers to run lower in late summer and drier forests, which are more susceptible to wildfire.

Despite the challenges, Fuller could not imagine living anywhere else. Fuller says the park still offers important lessons to other parts of the world, including the UK.

Fuller considers himself a proud anglophile. He spent one of his college years at Leeds University. A few years later, he fell in love with Angela and married her. They spent time in Uganda and raised two daughters in Yellowstone, home schooling them into their teens.

With the Yellowstone ecosystem holding the distinction of having the largest concentration of mammals in the lower 48 states, lessons in how humans and wildlife can better coexist abound.

Fuller shares stories of the bison that recently trudged past his window and rested in the snow near a walkway leading to his front door, and of grizzlies, including mother bears with cubs, ambling around his “wild neighbourhood”, or seeing the aftermath of a successful wolf predation on an elk, and foxes and coyotes routinely mousing in the meadows.

Fuller knows that many animals in Yellowstone can be dangerous, and he is under no false illusion about them seeking close human companionship, as one might see portrayed by Hollywood. He has never been injured, but he often gives wildlife a wide berth out of respect for their space.

“The older I’ve become, the more I’ve begun to appreciate the sentient connections between living things here and the places they inhabit,” he says.

“In 1872, when Yellowstone was created, I don’t think the US Congress could have possibly imagined how vital, as a symbol, this place would be in our time. Protecting nature for its own sake was a remarkable expression of foresight that we are only now beginning to fully understand.”