Lori (Yvonne Strahovski) and Nick (Eion Bailey), a couple of milquetoast newlyweds, can't secure the backcountry permit required to ride some mules down into the Grand Canyon. Because this is an opportunity that may never come again (??), they decide to follow a grizzled, alcoholic guide who offers to take them since he has a permit, by which he means he does not have a permit.
A day into the trip, a rattlesnake bite means the end of the guide. The mules done run off, so Lori and Nick have to find a way out on their own. After a few more days of wandering, a foot amputation, and multiple wolf attacks, we the audience (or, I suppose, me the audience) try to pretend we don't know that there aren't any fucking Timberwolves in the Grand Canyon and that at that time of year in the Canyon, our heroes would have died of dehydration long before the movie was over. That might have been nice, because it would have spared us the dreadful dialogue.
For a film purportedly about, you know, survival and man versus nature and all that shit, there's not much tension. The attitudes of these two doofuses aren't appropriate enough for a life or death situation; I suppose their incessant joking and light-hearted banter are meant to make each other feel better, but, you know. A little anger or panic once in a while miiiight be a natural reaction to being stranded at the bottom of the Grand Canyon with no fucking food or water.
The scenery is nice (duh), but otherwise I say skip it, skip it, skip it. Play Mass Effect 2 or watch Chuck to get a dose of Strahovski, read Over the Edge: Death in Grand Canyon, and watch a National Geographic special on the park instead. Or simply go there yourself. Just bring lots of water and don't be a moron about it.