Polar soil scientist Jim Bockheim has spent more than three decades trekking to the ends of the earth to study how soils form in extreme climates. But these days, the ends of the earth are becoming more crowded.

In 2006, nearly 30,000 travelers journeyed to Antarctica to see penguins, whales and the South Pole. These excursions, which range from $4,000 to $30,000, offer eco-tourists a chance to visit one of the world’s last great frontiers, communing with seals and climbing unnamed mountains.

But Bockheim—who himself has a mountain in Antarctica named for him—worries about the impact of this activity on a fragile ecosystem. Antarctica’s perpetually frozen soils have been likened to soils on Mars because they contain almost no moisture and are easily eroded. Thus, he says, they are highly vulnerable to human activities.

To Bockheim, those soils are like an archive of the planet’s glacial cycles, which he can read to assess what happened to bring on previous glaciations and make predictions about future climate changes.

He is now collaborating with colleagues from New Zealand and several international organizations to develop comprehensive maps of Antarctica’s permafrost and soils, with the goal of creating a trail system for visitors. “If tourism becomes more extensive,” he says, the maps can show “where the best place would be to lay these trails out with minimum impact.”

But tourists aren’t alone in beating a path toward Antarctica. McMurdo Station, Antarctica’s largest settlement, now hosts at least 1,000 scientists and support staff year-round. Bockheim says there’s growing awareness among scientists, as well, that care is needed to preserve the continent’s resources.

“Every time I dig a soil pit, I’m conducting some kind of disturbance,” he says. “So now, we dig the soil layers very carefully and put them on a tarp.” After collecting samples and data, his team gently replaces all the soil and stones. They even pack out their own human waste.

Although it takes days for Bockheim to reach his research location in Antarctica’s Dry Valley, the trip is always worth it, he says.

“It’s spectacular,” he says. “I’m interested in life at the extremes.”