1970s photographs show facility before it was reborn for science
Tom Regan revisits photographs he took in the 1970s to see areas of the facility that are being transformed today
On a nondescript day in the 1970s, Tom Regan tucked a small, disposable film camera in his lunchbox before his twelve-hour shift in the deep-level drifts of Homestake Gold Mine. Then a young miner, Regan was fascinated by the atmosphere of the mine, the powerful equipment he operated and the people—or as he calls them, “characters”—who worked alongside him. For more than three decades, he documented daily life at Homestake in hundreds of photographs.
Looking at a spread of those photographs today—some under-exposed and blurry, but all with careful handwritten captions on the back—Regan chuckles at a skinny young man with thick, dark hair: himself.
“Who'd have known when I took these pictures that I'd be looking at them this many years later?” Regan mused. Although Homestake closed the mine in 2002 due to the declining gold market, Regan still works at the facility, which has been transformed into the Sanford Underground Research Facility (Sanford Lab).
In January 2020, underground crews at Sanford Lab finished a four-month project of reopening the 6 Winze Ore Pass that connects the 4850 Level to a skip pocket in the Ross Shaft. This passageway will be used to clear excess rock during future excavation for the Deep Underground Neutrino Experiment, the largest physics experiment ever attempted on United States soil. The pilot hole for the 6 Winze Ore Pass was originally drilled in 1976, by a young man with dark hair and a camera in his lunchbox.
Deepening the mine
In the 1970s, the price of gold gradually was gaining ground. At $36.50 per ounce in 1970, it carved a jagged path up the charts to $677.97 per ounce in 1980. Meanwhile, Homestake was deepening the mine, following the gold ore body further into the earth’s crust.
“At rock flow meetings, we talked about the rock—where the ore was coming from to the moment gold was poured. Rock was the lifeblood of the mine. If it wasn’t moving, the mine was dead,” Regan said.
Around the same time gold prices were rising, Homestake approved sinking 6 Winze, an underground shaft, from its hoistroom on the 4550 Level to the 8100 Level, with other levels extending into the ore body every 150 feet between. To deepen 6 Winze, Homestake needed to get rid of excess rock that accumulated from the excavation of the shaft and new levels.
Creating the ore pass
The people working on 6 Winze moved, or “skipped” excess rock and ore to the top of the shaft at the 4550 Level. Because 6 Winze didn’t reach the surface, the ore and rock it hoisted needed to be transferred to another shaft. To make this transfer of rock possible, Homestake created the 6 Winze Ore Pass.
“Tom’s early work, especially with the borehole raises, created some of the final infrastructure elements to deepen the mine to the 8100 Level,” said David Vardiman, geotechnical project engineer for Sanford Lab who began working at Homestake in 1977.
Regan and his partner Dale Leistra drilled the pilot hole for the 6 Winze Ore Pass.
“Dale picked me up as a helper in 1972 or so. We were partners for a long time, working together in one capacity or another until he retired,” Regan recalled. “He was one of my best friends.”
The two partners worked on a series of openings that connected the top of 6 Winze diagonally to skip pockets near the bottom of the Ross Shaft. Regan and Leistra used a borehole machine to drill the final 12 ¼ inch pilot hole to connect the 4850 Level to the skip pocket.
“You know, at that time, I wasn't in the design talks,” Regan said. “I was a worker bee. We just set up, drilled the borehole and moved on to our next project.”
Once the pilot hole had been drilled, they removed the 12 ¼ inch drill bit and threaded a reamer onto the drill string.
“The reamer has a tri-cone bit with tungsten carbide buttons that rotate in a saddle. As the reamer rotates, the bit rolls against the rock and cracks it into little slivers of rock about the size of your thumbnail,” Regan said. The reamer widened the pilot hole, turning it into an ore pass 60 inches in diameter.
With its completion, rock hoisted from deep levels was dropped down the 6 Winze Ore Pass, using gravity to transport the rock hundreds of feet into the skip pocket in the Ross Shaft. From there, it was hoisted to the surface, crushed and processed. Over time, as abrasive rock constantly tumbled through, the ore pass widened to nearly three times its original size.
In 1975, 6 Winze reached the 8100 Level—the deepest Homestake would ever reach into the earth. With the use of the 6 Winze Ore Pass, Homestake continued mining the “deep country” levels for more than two decades.
A new purpose
In 2003, the year after Homestake closed, the pumps were turned off, allowing water to filter up through the shafts. It spilled onto the levels and washed debris throughout the mine. The 6 Winze Ore Pass filled with a sand mixture the mine had used to backfill stopes. Now, years later, it has been reopened.
The same ore pass that made it possible to deepen Homestake will play a critical role in the excavation for the United States flagship particle physics experiment, the Deep Underground Neutrino Experiment.
Refashioning mining spaces for science research is an ongoing phenomenon at Sanford Lab. Here, dark matter detectors are lowered down mine shafts, old shops house class-100 clean rooms and far-reaching drifts are microbiology collection sites.
“It's surreal. I was just 22 years old in that photo,” said Regan, who is currently a safety consultant at Sanford Lab. “Who would have ever thought that this work would be completely repurposed? But I guess I've felt that way since this place reopened.”