The Australian Outback remains formidably wild. Tom Huth takes a new train deep into it—and follows the path of two expeditions that discovered just how perilous this land can be.

The train pulls out of Sydney an hour and a half late. But who cares? From my compartment, I can spy the new Australian dreamtime, peering into people's backyards as the city's terrace houses give way to the modest bungalows of the suburbs, each yard arranged around its trusty clothesline tree.

This is my fourth trip Down Under. Still, I keep forgetting how contentedly middle class the Ozzies really are. I had imagined carousing in the train's bar car with jolly swagmen and crocodile hunters. Instead, I'm trading pleasantries with a herd of pensioners who have never crossed the country before. Beyond their agreeable heads, a hazy panorama streams past as we climb into the Blue Mountains. But the afternoon is dissolving into a rosy dusk, and life can't get much better: the lounge car feeling swank with its comfy club chairs and historical photos, the trunks of gum trees rushing past, glowing white.

This train, the Indian Pacific, crosses the continent to Perth. But I'm getting off in Adelaide after twenty-four hours, then taking another storied line, the Ghan, north through the unconquered Outback for 1,850 miles to Alice Springs and beyond. In 2004, the Ghan began running on new rails all the way to Darwin. Along the way there's a story to tell, because the Ghan makes the same journey—from south to north, from sea to shining sea—that Australia's most famous explorers made in the 1860s under inconceivable hardship. It's an epic tale of colonial ambition, of how rival expeditions—one led by the veteran John McDouall Stuart, one by the greenhorn Robert O'Hara Burke—raced to reach the northern coast and establish a route for a telegraph line that would connect Australia's white settlers to each other.

In an age when the United States was being mapped from east to west—twenty years after John Charles Frémont scouted emigration routes through the Rockies, ten years before John Wesley Powell and his men first ran the Colorado River through the Grand Canyon in wooden rowboats—these men half a world away were the Lewises and Clarks of their country's gathering destiny.

When I get to the end of the line in Darwin, I'll have a chance to, as they say, go out bush. Two fun-loving guides are taking me deep into the swamps to find the route of the explorer who won that long-ago race, and to follow his tracks to the sea.

After a three-course dinner I steal back to my compartment, remake the bed so I can lie down looking out the window, and turn off the lights.

At 4:45 in the morning, we cross the Darling River and pass the outpost of Menindee—just a brief parade of streetlights and darkened houses, the blur of a concrete station. Then the window goes black again, save for the glow of the dining car spasming against the passing brush.

October 1860. Menindee is a frontier town, the white man's last settlement on the way north from Melbourne. The Burke party rests here after a contentious fifty-six days in the saddle. The nineteen men don't know how to live off the land, so they have to haul everything with them—eight tons of food, six tons of firewood, a bathtub—in wagons pulled by camels imported from India. One wagon can even be converted into a boat in case they find that dreamed-about inland sea.