PORTLAND, Ore. — The estate sale brimmed with photo negatives and slides, military memorabilia, antiquated mountaineering gear and a box that so intrigued Larry Clark he sprang for the $4 price. Its label read simply “zoo.”

Good thing he snagged it: Images, memos, letters and yellowed news clippings inside the box fill in missing pieces of Oregon Zoo history. The unexpected archive provides glimpses into how things were in the 1950s and ’60s, and illuminates ways that science and husbandry have changed zoo operations. Plus, its contents make you wonder how things might have been if some outlandish ideas had taken hold.

Imagine, for example, Packy, the zoo’s prize elephant, confined to a dungeon because of his frightful behavior.

Or a proposal to use pachyderms to help log Northwest forests.

But first things first.

Clark, a Southeast Portland antique dealer, routinely peruses estate sales. In November, he spotted one across the street from his grandparents’ old place in Vancouver, Wash.

Years earlier, he’d known the homeowner enough to exchange a smile or a wave. But walking through the man’s house, he wished he’d known him better. “Somebody cool lived here,” he remembers thinking.

Clark is too young, at 49, to recall the hoopla surrounding April 14, 1962, when Portland’s zoo welcomed wobbly little Packy, the first elephant born in the United States in 44 years. And he had no idea that his grandparents’ neighbor was Leverett G. Richards, The Oregonian reporter who shot countless photos and produced reams of copy about the big delivery, among other topics.

Richards wrote for The Oregonian from 1931 until long after retiring from the newsroom in 1986. He died in 2000 at 92.

Clark nosed through the box he bought, scanned the most interesting photos into his computer, then gave the contents to Carli Davidson, his neighbor. Davidson, a commercial photographer, volunteers twice a week in the zoo’s photography-videography department.

“I spent all night reading through all the papers,” said Davidson, 29.

The artifacts, she says, “gave me lots of insight into … the beginnings of the Oregon Zoo, and what made it so famous — its elephant program.”

She lugged the box along on her next volunteer day and gave it to Michael Durham, manager of the zoo’s image library.

In recent weeks, he has picked through envelopes of negatives, prints and slides, scanning the best into his computer and adding them to the zoo’s digital files.

“When we find something like this,” Durham said, “we see it as very valuable. It fills in bits of the record that we didn’t have … Back in the ’60s and ’70s, we didn’t really document that much.” Now, he said, “the zoo is trying to be conscientious about our history.”

Richards’ files reveal a cast of quirky characters who worked at the zoo during an era when the nation was racially segregated, the space race was on and turning wild animals into captive specimens was widely accepted.

Notes and stories provide insight into Jack Marks, the zoo director of that era, Matthew Maberry, then zoo veterinarian, and Morgan Berry, the elephant importer and trainer who supplied the zoo its original Asian elephant herd.

Clippings detail the drawn-out wait for Belle to deliver Packy, a mystery given that keepers didn’t know that Asian elephant gestation lasts 22 months.

Richards saved Doug Baker’s Sept. 20, 1963, Oregon Journal column, in which Baker declared, “Packy, the darling of zoo visitors last summer, hasn’t been seen by zoo goers this year. In truth, it’s doubtful that Packy will ever again be a part of the Portland zoo’s elephant herd. … Packy is living in solitary confinement in the old zoo ‘dungeon’ at Washington Park.”

Packy was 17 months — about the same age as the zoo’s newest elephant, Samudra.

Keepers apparently hadn’t the know-how to safely handle a growing and potentially dangerous bull elephant.

Yet, as visitors know, they figured it out. Packy, Tusko and Samudra routinely move through the elephant yards today, exercising and mingling with the females.

Richards’ files also hold a letter from Don Clark, manager of the Seattle-based Northwest Hardwood Association, to Tom McCurdy of Portland’s Pacific Reforestation Inc.: “Is it possible,” Clark asked, “the Portland zoo might allow Thonglaw (another bull elephant) to be used for experimental logging in the vicinity of Portland?”

An April 30, 1963, clip from The Oregonian raises the same question, but there was a hitch.

“Thonglaw isn’t himself right now,” the article notes. “He’s been in ‘must,’ a form of elephant insanity accompanied by amnesia.”

Keepers today, of course, know that must, also called musth, is a normal hormonal surge that can result in highly aggressive behavior.

But that’s another story.