In the new film Night Moves, three Oregon-based eco-warriors (played by Jesse Eisenberg, Dakota Fanning and Peter Sarsgaard) watch anxiously from a small boat, as a car pulls up.

The triumvirate of activists have just planted a bomb under a landscape-destroying dam. But they hadn’t counted on fatalities. Should they return to the scene of the crime and disarm the explosive? Or should they chalk it up as collateral damage?

There's nothing like an unexploded bomb to keep an audience in palpations. But it is an unexpected device – in every sense – to find in a Kelly Reichardt picture.

Does she has a favourite use of the trope?

"It has to be Battle of Algiers," she says. "It's all about the details. You don't remember the explosion. You remember her little foot pushing the bag under the chair."

Details matter for Reichardt. Over the past 10 years, she has established herself as America’s foremost practitioner of slow cinema. Her work is far more redolent of Iranian or Turkish arthouse, than of any of her compatriots’ output.

“I do love Iranian and Turkish films,” says Reichardt. “It’s just a pace I can relate to. I don’t consider what I’m doing to be slow cinema. But I consider a lot of new films too fast for me. I want to sink in to things. And I always think: ‘can’t you just trust me as an adult? Can’t you stop waving in my face to keep me entertained?’ So I treat my audience the way I want to be treated.”

In this spirit, Reichardt consistently deconstructs genre and audience expectations: Old Joy is an alt-country ballad riposte to the men-children who populate the Apatow bromance milieu. Meek's Cutoff pares back the western to its most arid and tactile. Wendy and Lucy is a stalled road trip featuring only a girl and her dog. The films have all been critically lauded, have played at Sundance, Venice and Berlin, and won hatfuls of awards. Reichardt herself has received a Guggenheim Fellowship and is an artist-in-residence at New York's Bard College.

In theory, Night Moves, a political thriller, ought to be the director's most mainstream offering to date. In practice, it's a thornier prospect. The new film's characters, despite good intentions, are a ghastly bunch: Sarsgaard's H isn't nearly as smart as he maintains, Fanning's convictions are shaky and funded by her wealthy parents, Eisenberg's Josh is as cold-blooded as he is self-interested.

I have a theory. Does Josh lose his mind as the picture goes on, I wonder? Is he really conversing with H or is it all in his head?

“That’s an interesting idea,” laughs Reichardt. “But I don’t think of Josh as having that much of an imagination. He’s kind of this super fundamentalist. But a fundamentalist on the left. He has an overarching confidence in his ideology and his decision making and in his take on things. He doesn’t think beyond that.”

Reichardt has a reputation as an actor's director, who has coaxed career best performances from Michelle Williams, Will Oldham, and Zoe Kazan. The process of directing Jesse Eisenberg was a little more collaborative, she says. In order to get into character the actor moved into the Portland farming cooperative depicted in the film.

"He will ask you more questions than you could imagine," says the director. "Jon Raymond, my writing partner, and I went out to the farm, which is owned by friends of ours, to see Jesse. We all went to an activist meeting together and we incorporated some ideas Jesse had. That's not normal for us. We like to stick to the script. But process never stops for him."

Reichardt’s fifth feature has not necessarily played well with her traditional independent constituency. Post-screening Q&A sessions have, notes Reichardt, been dominated by heartbroken young women, who cannot understand why the director is taking a swing at eco-activism.

"Jon and I are both close to Todd Haynes, who often produces our movies. So we both go running to try to get him on our side whenever we come to a stand-off over the script. I remember even Todd said: 'Why do you have to pick on the Left?' And I was like 'Oh. Todd, come on. Don't make me suffer'. We really had to put our own political agendas aside and hunker down. The idea of making a film about fundamentalism that was aligned with the Tea Party wasn't interesting for either of us."

This is Reichardt’s fourth collaboration with Raymond: they can’t need to go running to Todd Haynes all that often, surely?

“Like any relationship it’s intense. We’re taking a break from working with each other right now. We’re very close in life. I’m incredibly close to his children and his partner. Those relationships are some of my favourite things in my life. But you do end up talking about each project too much.”

Kelly Reichardt was born in the late 1960s to a family of police officers. Growing up in Miami, Florida, she found herself in a minority demographic in a state of retirees. The family were different but in the straightest way possible: her father worked the crime beat in Dade County and her mother was an undercover narcotics agent. Often, Kelly and her sister would stay hunched in the back seat of the family car. The vehicle make and model changed frequently.

“The only books in our house were crime books,” recalls Reichardt. “I often wonder what I would have been like if I had been taken around galleries as a kid. But that wasn’t my family at all. That was stuff I had to negotiate by myself.”

Where did that artist’s sensibility come from, if not from officers mom and dad?

“I don’t know exactly. My sister is a bookkeeper. My dad did love jazz. And my mom always had some craft project on the go. I got into photography very early because we did love camping and driving. We’d drive from Miami to Montana and I’d take pictures all the way.”

It's a talent that would come in handy later on. Discerning viewers have come to think of the film-maker as America's poet laureate. Her tableaux are striking in a way that makes the viewer think of Burke's treatise on the sublime rather than Norman Rockwell. The road trip in Wendy and Lucy looks unwelcoming and harsh; in Night Moves, the landscapes that that the activist's wish to save are as grey and post-industrial as the grimmest shots in Stalker.

"Vietnam was always on TV when I was growing up," she says. "So that was a big influence. I was never one of those people who were brave enough to work from a frontline. But I did soak up photography and landscape. I drive from New York to Oregon four times a year. So I'm scouting for locations even when I'm not. That's a huge part of the process. I'll write around locations. They'll reflect back the character or story. I spent a year-and-a-half scouting for Night Moves."

All but two of Reichardt's films are set in Oregon and feature protagonists who are battling against a lack of resources. It's a very different Oregon to the hipster capital depicted in Portlandia.

"I hope you're right," laughs the director. "We were having an early screening and I really wasn't sure if we should invite Carrie (Brownstein, Portlandia's creator and star) and her friends so far ahead of release. Because for us Portlandia is a bit like The Simpsons is for the rest of the country. You can work for something on years and – oh shit – they'll get it, repeat and clobber it in a three-minute sketch. It's amazing really. But we did invite them in the end."

That seems only right. Night Moves, in common with Brit Marling's The East, invites in the usual liberal, left-leaning suspects, only to probe their beliefs. For the moment, Kelly Reichardt is happy to weather the storm.

“I knew there’d be a certain amount of blowback. But we had a goal. And we don’t want to feed you with what you’re already comfortable with. When you’re making a film it should feel like there’s a real chance that it won’t work and you will fail. It should be a bit scary. For everybody.”