CUPERTINO — Apple employees agonize over every last detail in the designs of their sleek gadgets, and their future corporate home — a gleaming loop of glass that calls to mind some sort of spacecraft — has been treated no differently.

So when construction wraps up in 2016, passers-by can be forgiven for stopping to wonder: Why has the flying saucer landed next to a century-old barn?

Underscoring that Apple Campus 2 is at once one of Silicon Valley’s wildest sketches of the future and a portal to its past, the company has set aside a place on its state-of-the-art campus for the Glendenning Barn, named for a pioneer family whose land became a magnet for tech companies after the blooms faded from their orchards. Constructed in 1916 with planks of redwood, the barn was built to last, though its founders couldn’t have foreseen all that it would withstand: the decline of local agriculture, the rise of big tech and several changes of the guard in Silicon Valley, not to mention Apple’s earth movers.

In the years before his death in 2011, Apple co-founder Steve Jobs decided that he wanted to tear up the husk of Hewlett-Packard’s cement-laden campus — particularly the massive parking lot — and bring the land back to its roots, when it was known as the Valley of Heart’s Delight for all its orchards and flowering trees.

When finished, the 175-acre site off Wolfe and Homestead roads in Cupertino will be transformed from 80 percent asphalt and concrete to 80 percent greenery and open space. Considering all that, former Cupertino Mayor Orrin Mahoney notes, an agrarian artifact won’t seem out of place at all.

“When they’re finished, the land will look much more like it did 50 or 100 years ago than it looked five years ago,” he says. “The barn fits into that.”

To protect the structure during construction, Apple carefully dismembered the barn, numbering it piece by piece — every plank, nail and crossbeam — so it can be rebuilt just as it was, says Donna Austin, president of the Cupertino Historical Society. The company has even stockpiled redwood salvaged from an old grove in case any damaged planks need to be replaced.

Under Apple’s care, it will be a working barn for the first time in decades, storing sports equipment and the landscaping supplies the company will need for the thousands of trees that will shade the campus. Jobs told the Cupertino City Council he’d like to plant some apricot trees. They’re the same kind of trees Bernice Glendenning Jones tended as a young girl many years ago, before tech took hold of the land.

Robert Glendenning settled in the Santa Clara Valley in 1850, staking out about 160 acres of land soon after, according to notes supplied by the Cupertino Historical Society. The land passed from Glendenning to Glendenning until the descendants pooled their acres with other farming families to form the Vallco land consortium in the 1960s. From there, the lush acres became the preferred headquarters of the valley’s reigning powers: from Varian Associates to HP to Apple.

Jones traces the history of the land sitting in her wooded Cupertino home, a newspaper on her lap. Most people know her as Beez, a nickname that has stuck with her since she was 2 years old, when her sister couldn’t pronounce her name.

Life in Cupertino revolved around the orchards in those Depression days — school started each fall when the fruit was in, says Jones, a slender woman with white hair that falls around her shoulders and bright blue eyes. Whole families would help out with the harvest, even small children, who rolled up their shirts to carry the apricots they picked.

“I started in the fruit when I was big enough that I could cut ‘cots,” Jones says.

She still keeps one of the special knives used for the task in her kitchen.

After traveling the country with the Navy, Jones returned to Cupertino in the 1970s and worked with the historical society to add the barn to the historical registry. From the time she was a girl, the old barn was a source of great fascination, holding horses and flatbed wagons in which she used to ride. But its contents were mostly a mystery to her — children were not allowed to go inside.

“Wouldn’t you be curious?” she asks coyly.

After HP bought the land from Varian in the early 1970s, much of what Jones remembers — the acres and acres of apricots, the rambling farmhouse — gave way to an office park. The company was growing like a weed, having just entered the computer business. But it never encroached on the barn.

HP prepared the barn for the future, reconditioning it, replacing the roof and laying a new concrete foundation, says Ed Miller, who was then the company’s computer manufacturing manager. Once spruced up, the 1,900-square-foot barn became a focal point of company social life, the site of the annual picnic, retiree reunions and frequent “beer busts,” says Mahoney, the former Cupertino mayor, who spent most of his 35 years at HP working on the Cupertino campus.

Before Jobs publicly detailed plans for Apple Campus 2, Mahoney and other public officials got a glimpse of a model. After a briefing by Apple CEO Tim Cook, then the company’s chief operating officer, Mahoney says he had one overriding concern: What about the barn?

Cook reassured Mahoney that Apple was well aware of the historic barn but still figuring out the best place for it. Planners ultimately settled on placing the barn near the new Apple fitness center, a place that’s sure to be a hub for employees — and still in public view.

Long retired from HP, Miller, an 82-year-old Los Altos resident, had not heard what would become of the barn after his company sold the land. He was relieved to hear the spaceship and the barn can coexist.

“I’m anxious to one day see it again,” he says.

Contact Julia Love at 408-920-5536 or follow her at Twitter.com/byjulialove.