Given pioneers' near mythological status, it's easy to forget that it would've sucked to be one of 'em. Sure, adorable li'l Laura Ingalls might have bonded with her loving family as they built a little house on the prairie, but also... y'know... DONNER PARTY.

That frontier life of unrelenting suckitude is excruciatingly well rendered in Meek's Cutoff, the latest from director Kelly Reichardt and writer Jon Raymond, the duo responsible for two other Oregon-set dramas, 2006's excellent Old Joy and 2008's mope-tacular Wendy and Lucy. Here, Reichardt and Raymond tell the harrowing tale of several pioneers—including Solomon and Emily Tetherow (Will Patton and a great Michelle Williams), Thomas and Millie Gately (Paul Dano and Zoe Kazan), and William and Glory White (Neal Huff and Shirley Henderson)—who're lost on the unforgiving Oregon Trail.

Well, anyone with common sense would say they're lost, anyway, no matter how insistently their guide, Meek (an unrecognizable Bruce Greenwood), grumbles stuff like "We're not lost; we're just findin' our way." With his vague excuses and vaguer plans, Meek—whose gruff countenance and rambling mutterings place him somewhere between Jeffrey Lebowski and one of Deadwood's bar toughs—would be an okay guide, if it weren't for the fact that his tired, ill-prepared pioneers are running out of food and water. And then things get even worse when the increasingly badass Emily refuses to let Meek kill a Paiute they've taken as a hostage.

Patient and ominous, Meek's Cutoff feels less like a western and more like a thriller that plays out in slo-mo. Like the journey it documents, the film is grueling and wearying, but unlike most cinematic endurance tests—Wendy and Lucy comes to mind, actually—it never gets so bogged down in life's inherent ugliness as to celebrate it. Beautifully shot, impressively acted, and unexpectedly haunting, Meek's Cutoff isn't just a reminder that we're lucky to live in the West in a time when we don't have to worry about repairing wagons—it's also a film that'll probably turn out to be one of the best of 2011.