The call of the wild need not always include dog sledding, gold prospecting or grizzly rasslin'. In "Heroes of the Frontier," Dave Eggers swaps the classic man-vs.-nature theme for a middle-class-mom-vs.-societal-expectations adventure.

Thirty-eight-year-old Josie flies her two young children from Ohio to Anchorage to escape an extinct marriage, a flamed-out career as a dentist and her own fractured childhood. She has $3,000, a credit card, a phone, a dilapidated rented RV and no clear idea how long she and the children will stay gone.

Their madcap trip falls in that gray area between a family vacation and a kidnapping.

For Josie at the outset, "Alaska was at once the same country but another country, was almost Russia, almost oblivion." With its snowy peaks, mighty ocean bays (some now lined with cruise ships) and smoke-belching forest fires, it certainly is a long way from small-town Ohio, where Josie and "invertebrate, loose-boweled" Carl raised their children Ana and Paul, now 5 and 8. Carl has some time ago decamped to Florida, taken up with another woman and asked for permission to bring the children down there for a visit, which precipitated Josie's heading for the hills.

One of the best things about "Heroes" is Josie herself. She runs counter to the traditional travel/escape narrative by the mere fact of her gender and her being a mom with kids in tow. She wins our respect through her grit, her admirable way of interacting with her two energetic and intelligent children, her confidence and her resolve. She also sometimes drinks too much and has a knack for putting the three of them in situations (breaking into a cabin, an incident with a flat tire and a prison work gang, getting caught in a storm on a day hike) that appear fraught with hazard. But most of them are resolved with acts of human goodness or charm, not bodily harm.

If Josie isn't bipolar, she certainly is emotionally labile, one minute castigating such mile markers of western civilization as helicopter parents, 21st-century yuppies, the spineless and the litigious (she was sued for malpractice by a patient), and the next moment reveling in spotting a fox during a bike ride in dusk's witching hour or envying the unbridled happiness of revelers at a rural Mennonite wedding. Almost schmaltzy at times, Josie is open to miraculous small events in an unfashionable way that is openhearted, generous, humane. Her social critique, while sometimes scattershot, often hits the bull's-eye.

Although "Heroes" is told from Josie's point of view, her children are more than merely along for the ride, and en route Josie "began to conceive a new theory of parenting" in which the natural world plays a bigger role. The mark of success was not to "give my child an Ikea desk and twelve hours a day of sedentary typing … while outside the sky changes, the sun rises and falls, hawks float like zeppelins." Instead, she resolves to "remind them of joy. Document joy, tell tales of joy at bedtime, take photos and write diaries. Journals of joy that could never be denied or conveniently forgotten."

The children — wise-beyond-his-years Paul and wild, red-haired, accident-prone Ana — are sketched with a sensitive ear for their peculiarities.

The novel's picaresque aspects, the situations and people whom Josie and the children encounter on the road, unfold easily and are mostly done very well, with only occasional detours into what come off as ham-handed authorial intrusions in which we are told the import of a scene or circumstance, even when we are pretty much there through narrative alone. As if in a rush to summarize the story's bigger meanings, these examples multiply near the finale, a ripping yarn told under a thunderstorm as big as all Alaska.

Claude Peck is a Star Tribune night metro editor. Follow on Twitter: @ClaudePeck

Heroes of the Frontier
By: Dave Eggers.
Publisher: Alfred A. Knopf, 385 pages, $28.95.