It’s pretty easy to paralyze America’s oil infrastructure. All Emily Johnston and Annette Klapstein needed was a set of 3-foot-long green-and-red bolt cutters. And a willingness to go to jail for years.

On October 11, 2016, as they pulled up to an oil pipeline facility in the farm fields outside Leonard, Minnesota, the pair were bent on taking direct action to address climate change, since, they figured, the US government had failed to do anything about it. “This is the only way we get their attention,” Klapstein said on video before she got out of the car. “All other avenues have been exhausted.”

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By “their,” she meant policymakers and oil companies (and, by extension, you and me). Johnston, now 52, is a poet and cofounder of the Seattle chapter of climate action group 350.org. For years, she’d done all the things law-abiding climate change activists do: filed petitions, lobbied legislators, hosted speakers, wrote letters, blockaded refineries, and tried to block Shell from moving their drilling rigs into the Arctic. Klapstein, 66, is a retired attorney from Bainbridge Island, Washington, whose job was to protect fishing rights for the Puyallup tribe. With her group, the Raging Grannies, her actions included blocking oil trains while chained to a rocking chair. They’re both white, middle-aged. Law-abiding folks. Except when they’re mad.

It was a cold morning, aspens shaking their dull gold under heavy skies. A fellow activist, Ben Joldersma, livestreamed to Facebook as the two women cut the chains around fenced enclosures containing large shut-off valves for two oil pipelines owned by the Canadian multinational Enbridge. The pipes carry crude oil from deposits of tar sands (also referred to as oil sands) in Alberta, transporting it to Lake Superior. Because making petroleum products from this goo—called bitumen—releases more global-warming emissions than most other oil sources, the activists were going to do what they could to keep it in the ground.

about the author Dean Kuipers writes about the environment, politics, and the arts and is the author, most recently, of a forthcoming memoir, The Deer Camp.

Enbridge was well aware they were there: About 15 minutes before they cut their way in, an activist named Jay O’Hara with the Climate Disobedience Center in Seattle had talked to Enbridge staff on the phone and warned them that protesters were going to be closing the valves on Line 67 and Line 4, each of which hum with 33,000 gallons of crude oil per hour.

What only a handful of people knew, however, was that Johnston and Klapstein were part of a nationwide action dubbed #ShutItDown that would also choke off pipelines at three other locations in North Dakota, Montana, and Washington State that day, moving east to west. They referred to themselves as the Valve Turners, and Reuters called their effort “the biggest coordinated move on US energy infrastructure ever undertaken by environmental protesters.” On that day, five principal activists—Michael Foster, 54, Ken Ward, 61, and Leonard Higgins, 66, in addition to Johnston and Klapstein—cut off 70 percent of the oil from tar sands that flows into the US from Canada.

With the chains cut, Joldersma, 40, called Enbridge again and gave their names and location. Then he added: “For the sake of climate justice, and to ensure a future for human civilization, we must immediately halt the extraction and burning of Canadian tar sands. For safety, I’m calling to inform you that when I hang up this phone, we are closing the valves.”

Even as Johnston and Klapstein entered the enclosures, they could see and hear that Enbridge was already closing one of the valves remotely: A tall plunger or screw device was dropping as a gate shut in the underground pipe. On the other valve, they cut the lock on a large steel wheel that allowed for manual shut-off and cranked it for “I don't know, seven or eight minutes,” Johnston told me later, until it too was closed.

“This was what I needed to be doing, here in this time, facing this massive emergency," says Annette Klapstein, right, with fellow activist Emily Johnston. "That I was doing everything in my power to ensure that my children had a future." Steve Liptay Getting arrested was part of the plan. Steve Liptay

It took almost an hour for Clearwater County sheriff Darin Halverson to show up with some deputies. When he did, according to Johnston, he said, “Well, you don’t look too dangerous to me,” and arrested everyone, including videographer Steve Liptay, who was also present but whose charges were later dropped. No one was even cuffed.