You can see the mugging life has done on Ray Eddy, one of the two main characters of the stunning drama "Frozen River," from the way she sits in her car smoking a cigarette.

In the movie's opening scene, that's where we find Ray (played by Melissa Leo) - in a fuzzy pink housecoat on a snowy December day, fighting to keep from crying. The money she had stashed in the glove box is gone, taken by her gambling-addicted husband, Troy (who is never seen in the movie), on the day she was supposed to make the balloon payment on her new double-wide.

After work at the Yankee Dollar store, where she hopes to become assistant manager, she goes from her upstate New York town down the highway to the Mohawk reservation, finding Troy's Dodge Sierra in the bingo-hall parking lot. Moments later, she watches the Dodge being driven off by Lila (Misty Upham), a Mohawk woman who needs a car with a big trunk.

Lila persuades Ray to go across the iced-over St. Lawrence River, to the Canadian side of Mohawk territory -turning Ray into an unwitting accomplice in a human-smuggling operation. But Ray, desperate to get her double-wide and give her two sons a good Christmas, takes up Lila's offer to make more runs across the river to bring more illegal immigrants into the United States.

Writer-director Courtney Hunt, in a confident debut, grafts a crackerjack thriller with a fascinating cultural study of the uneasy relationship between tribal members and their white neighbors. Above all in this drama (which won the Grand Jury Prize at the 2008 Sundance Film Festival), Hunt nails the emotional toll of poverty, how people beaten down by a lifetime of scrimping can talk themselves into doing things that clash with their consciences.

Upham (who reportedly gained 40 pounds for the role) fills Lila, a widow fighting for custody of her baby, with a deep well of sadness. And Leo, a great supporting player (in "21 Grams" and on "Homicide: Life on the Street") getting the leading role she's long deserved, conveys Ray's long life of hardship and broken promises with slight, natural gestures. Their performances give "Frozen River" the raw emotion that drives home Hunt's powerful tale of survival on America's bottom rung.

Sean P. Means can be reached at movies@sltrib.com or 801-257-8602. Send comments to livingeditor@sltrib.com.