TORONTO — Choosing a follow-up project to her sleeper hit "Whale Rider" was no easy task for filmmaker Niki Caro. In summer 2003, when the film was released in the U.S., she and her architect husband had just had their first child, a daughter named Tui, after a bird in their native New Zealand. And suddenly scripts came piling in, at exactly the moment in her life when she had no time to read them.

"I got every script about a young girl and simultaneously every script about a large mammal," says Caro, who lives on the beach in New Zealand where "The Piano" was shot. She managed to read about three scripts a week for six months. "There was the story of a woman who traversed the Outback, with just four camels and a dog. There were scripts about elephants and caravans full of animals."

Caro insists she is simply very particular about the stories she takes on. "It's like falling in love," she explains. "And it's a committed, committed relationship with me and the material."

So Caro ditched the mammals and even her native land to settle on "North Country," which opens on Friday. The film stars Charlize Theron as an abused single mother who, in 1984, filed a class-action sexual harassment lawsuit in Minnesota against the mine where she and her father worked. As she did in "Whale Rider," Caro paints a candid, unsettling and original portrait of a strong woman who's up against the odds.

"Neither film sentimentalizes the journey," Caro says. "Both films look at life in a pretty tough, clear-eyed way. These are small communities that are troubled, but whose spirit is very strong and whose people are very good in their heart."

Caro has a particularly anthropological approach to her projects. "Have you ever seen the David Mamet film 'State and Main' when Hollywood comes in and f---s over a whole town?" she asks. "That's not me. Oh boy, I'm in danger of going dangerously in the opposite direction. Every time I make a film I completely fall in love with the people and the landscape and the way of life."