kindheartedWomanDavid Sutherland’s long form documentaries on the people of flyover country often take years to make. He first has to find the right people who will put up with him, follow them for years on end, and then edit the whole shebang.

The results are worthwhile, with the Nebraska-based “The Farmer’s Wife” and the Appalachian “Country Boys” now leading to the bleak reservations of North Dakota with “Kind-Hearted Woman” (PBS, 9 p.m., check local listings).

Here he finds a memorable spirit also known as Robin Charboneau, an Oglala Sioux living on North Dakota’s Spirit Lake Reservation. Divorced and raising two kids, she has a painful past of abuse as a child in her own family and in every foster family she was later assigned to. In trying to get a stable life at the reservation, she also battles to maintain custody of her children from her ex, who also abused her.

But it is only through the constant filming that we learn that her daughter as well was abused. And cameras are on when she tells her mom. About the time abuse allegations start flying with custody petitions, most cameramen begin packing up. But Sutherland stays on the scene, following the case and her moves, first to Fargo to go to school and then up to International Falls and across the Canadian border to an even more bleak reservation.

By then we’re fully engulfed in her life and given a glimpse of the hard living that’s done in the high plains. Still, there would still seem to be an ending spot at some point, maybe at the outcome of a court case, or as they move from one place to another. But the story just keeps going.

Which would be fine, except for the way that PBS likes to both promote and kill longform documentaries by showing what is this case more than four hours of film on two consecutive nights. They did the same thing last week by showing the four or five hour look at a year inside a D.C. school by showing in a similar two-night gulp. Who has the time to set aside two days to watch such a thing? The sheer length not only scares away audiences, but it also keeps coverage at bay as well.

Sutherland deserves better (maybe an hour weekly over a month), if only because there’s so much shared from a family you would initially identify as shy. Robin proves a hard worker who finds herself up against limitations. Her kids are bright spots in her life and the love they share is obvious. But later, it’s just as clear to see how separation is hurting the young boy, and how adolescence is difficult for the girl.

Social services outside the reservation seem helpful and find a place for her to eventually share her story through lectures. But the tribe itself is hostile to her plight, thinking that the film itself will put it in a bad light.

That it does, and thank goodness. In part because of the film, things have changed at the Spirit Lake Reservation, which has earned national shame for ignoring abuse claims. The real issues that come out of the singular human story are not well articulated — someone should point out that as a result of the filming tribal social services got a major overhaul, and that the violence against women act, recently signed into law, has jurisdiction over tribal law for the first time. (This reporting, as far as I know, only appears on the accompanying “Frontline” website).

Sutherland told reporters at the TV critics winter press tour in January that he hadn’t intended to initially tell a Native story, but he did want to tell a tale of abuse, something he said was in the background of “The Farmer’s Wife” and “Country Boys,” but he regretted not looking into more.

In finally picking Robin and her family, he said, “I just wanted you to get to know them up close. That’s all I’m ever going after. The issues of abuse were there, but the issues come out of the people. The big question is would Robin go the distance when I chose her.

“It’s a long, long process,” Sutherland said of his work. “There’s almost hundreds of thousands of audio clips. It takes six months to mix a film like this. A normal documentary, it’s a week. So I’m a dinosaur, but I’m also cutting edge.”

Sutherland’s focus on audio means that we can hear Charboneau’s sighs as she walks down the street or responds to her kids. We get a feel for the land where she lives through his thoughtful camera work, and the sounds of trains and dogs in the background.

Sutherland’s filming did made a difference, especially in her own life, Charboneau said.

“When he first came, he was talking to a little girl,” she said. “She didn’t have a voice. She didn’t have a she had a spirit, but it was gone. It was lost. She didn’t know who she was. She didn’t know what it was to be a woman and a mother. Even though she had children, even though she was married, she didn’t know none of that. And all of a sudden comes this crazy man who listened, who listened to me, who told me, ‘I can’t believe you went through that stuff.'”

Through that, she says, “I found my voice. I found my spirit. It’s alive. And I give it all to everyone wherever I go. He listened to a little girl when nobody else would listen to a woman. That’s what David did.”

“Kind Hearted Woman” plays tonight and Tuesday at 9 p.m. on PBS (check local listings).