Like a Sundance film from the early '80s (before the festival was so named), this Sundance prizewinner starts grim and finishes grim, with a whole lotta grim in between. It's based on Daniel Woodrell's 2006 novel about the sort of rural, meth-dealin' Missouri families who used to be called white trash; now we just call them Sundance fodder. Winter's Bone is essentially a save-the-farm movie, only here the farm is a disheveled home run by 17-year-old Ree (an effective Jennifer Lawrence), whose momma is catatonic and whose daddy is in jail (meth, natch). Without enough food or money, she tends two younger siblings; then the news gets worse. Dad's skipped bail, and the bail bond is the house. So unless Ree can find her fugitive pappy, she and the kids will be homeless and headed to foster care. Ree's quest among the homesteads of her extended family is a sullen tour of Ozark poverty and suspicion. She pleads kinship, and doors are slammed in her face (and worse). There's a tedious kind of integrity to the persistence of both Ree and director Debra Granik (Down to the Bone), but also a failure of filmmaking imagination. Winter's Bone just trudges forward through a world like Deliverance without the canoeists. (Its one good scene comes late, involving a boat and a corpse.) Meth would make the movie go faster.