When asked why he wanted to climb Mount Everest, George Mallory famously replied, "because it is there." In 1977, young Aussie contrarian Robyn Davidson walked across 1,700 miles of desert from Alice Springs to the Indian Ocean for a slightly more complicated tangle of reasons, including her disgust with so-called civilized society and her desire to be alone with only a dog and four camels for company, but the essence of her quest was the same.

"Tracks," Davidson's memoir about the journey published a few years later, became an international bestseller, particularly popular with women who admired her fierce independence in macho outback territory. To read such a saga is one thing; to make a movie about a long, slow haul across flat, desolate country that will intrigue and stir audiences from beginning to end is a much steeper challenge.

But nearly 40 years after the fact, director John Curran ("The Painted Veil") and his star, the formidable Mia Wasikowska, have followed the strategy Davidson used to hurl herself into the trek and done just that, aided by screenwriter Marion Wilson's mostly taut adaptation of the book.

Always compelling whether she's playing Alice in Wonderland, Jane Eyre or more modern heroines, the 24-year-old Wasikowska here embodies Davidson with a mix of maniacal idealism and childish stubbornness that makes it seem her chin is perpetually stuck out at the world. It's hard to judge who's more cantankerous, her or the four feral camels she trains to haul supplies for her and her beloved black dog, Diggity.

Australia, it seems, has the largest number of wild camels in the world, because they thrived after being abandoned as pack animals when trains and trucks took over. Growling, yawning, whimpering and acting out, the camels — you can almost smell them from your seat — afford some welcome comic relief.

As much of a misanthrope as she seems, Davidson is nonetheless inspiring in her doggedly defiant pursuit of an odd dream. In voice-over, she declares "I'd like to think an ordinary person is capable of anything."

"When it's just me, my animals and the desert, I feel free," she says. But she occasionally permits acceptable bipeds to hang with her. Adam Driver is nerdily fetching as Rick Smolan, the photographer who documented her journey for National Geographic, galumphing up to her in his jeep now and then to plant some water jugs or charm his way into her dusty blankets. And Roly Mintuma is a treat as Mr. Eddy, an aboriginal elder who temporarily acts as her guide and adviser.

But even in the middle of nowhere, totally off the grid in a time before cellphones and GPS, Davidson can't escape less pleasant intrusions of humanity. The eccentric quest of "the camel lady" has by this time attracted international curiosity. Tourists accost her to pose for photos, as do hordes of journos waiting for her at an unfortunate point in the trip. After making a heart-wrenching decision and losing one member of her little party, she goes primal, wandering naked and numb.

Mandy Walker's cameras take full advantage of the terrain's stark colors, textures and ever-changing light, so you feel the grueling monotony of her trudge without ever longing for a visual oasis to relieve the view.

"Tracks" is bound to draw comparisons to the more ballyhooed, upcoming "Wild," in which Reese Witherspoon plays author Cheryl Strayed, whose memoir of her own solo hike up the Pacific Trail is a much more recent bestseller. After witnessing Wasikowska's tour de force, its hard to imagine that even Oscar-winner Witherspoon can top it.

ktillotson@startribune.com • 612-673-7046