OUR CAMP AT UTUKOK was bare-bones. Everything had to be flown in and out by helicopters with extremely limited payload space. Everyone got their own North Face tent for privacy; communal space was provided by a canvas cook tent with a propane stove. As far as showers went, there was a deep hole in a creek about a mile from camp. The bathroom was an open-front plywood windbreak surrounding a plastic-lined hole in the ground.

Despite the lack of amenities, working at Utukok quickly became my favorite thing in the world to do. In the mornings (since it never got dark, "morning" seemed completely arbitrary), we'd get up and meet in the main tent. Over breakfast we'd look at maps. Mystery Man plotted out survey areas based on topography and watercourses, and conferred with Mad Mel about flight routes and landing zones. Slaughter and Mystery Man would head to one destination while Baker, Mylène, and I headed to another.

"Arrowheads don't yell out, 'Here I am! Come pick me up,' " Baker explained one day. He was walking ahead of Mylène and me about ten miles from camp, where Mad Mel had dropped us off along an unnamed tributary of the Utukok River. The crew had divided the entire NPRA into sections based on major watercourses, and this summer they were concentrating on the mountains to the south of the Utukok.

When the oldest site in the New World is found, it will probably be thanks to the shrewd eye of an arrowhead hunter like Baker. While much of Kunz's time is sucked up by managerial duties, each summer Baker is on the ground every day for a month or more. His grandfather and father were both archaeologists, and 17 years ago, when he was 45 and still working as an engineer, he earned a degree in anthropology from the University of Colorado at Denver to follow in their footsteps. Baker has found arrowheads in a dozen states; he and his father have amassed a collection of some 5,000 stone artifacts.

As I walked behind Baker, I marveled at his attentiveness. In a land of constant threats from rockslides and grizzly bears, he keeps his eyes locked on the ground as though a cable connected his chin to his chest. In the NPRA, Baker has seen everything from 2,000-year-old Eskimo artifacts to a Russian shotgun from the 1850s. But he's primarily interested in rock.

"What kind of rock are we looking for?" I asked.

"You're walking on it. It's this gray stuff. These nodule-shaped outcroppings are all chert, a tool-grade stone. But none of these rocks have been worked."

When Baker says a rock's been worked, he means that it's been modified by a human. Finding such artifacts is a complex skill. "First I'm looking for rocks that are out of place," he said. "If I'm on a hilltop covered in crushed shale and there's a lone, single flake of chert there, it didn't get up and walk there. Someone carried it in. So when I see a rock like that, it gets my interest."

We made our way across a steep slope covered in lichen. "There's nothing here," he said. "You wouldn't want to sit here and work on rocks. Ten thousand years ago, or whenever, people camped in the same places where you'd camp now: level areas with smooth ground, a good view of the surrounding country, access to fuel for fires, maybe overlooking where a couple rivers come together." Baker pointed to a bluff about a half-mile ahead. "We'll find something up there," he said.

And we did. The moment we climbed to the top of the bluff, Baker called Mylène and me. "This is a flake scatter," he said. The ground was covered in flakes of gray chert the size of a pinkie nail—the by-product of tool construction. Baker picked up a piece the size of the bottom of a coffee mug. "The surface marks that look like clamshells are the result of conchoidal fractures. Rocks can break from freezing and thawing, animals step on them—all kinds of things happen—but when you see a conchoidal fracture, you know it's a man that did it."

Random flakes don't excite Baker because they're not diagnostic; that is, the shape of the artifact does not signify the time period when it was produced. To a trained eye, the shape of a complete point—or even a broken tip—can tell you whether it's of ice-age vintage. And Baker reminded me many times, "I'm only interested in the really old shit."

Seconds later, Mylène picked up a rock. "Hey!" she yelled.

"Oh, looky there," said Baker. "You see how flakes were knocked off on both sides of that? That's what we call a biface."

"Is that how Clovis made them?"

"Yes, but so did many other groups."

He looked around for another minute. "OK," he said, "let's record this sucker." We wrote down the number of artifacts we found, along with their location and a brief description of topography and ground cover. Mylène paced off the bluff's diameter. "Fifty meters," she said. Before we left, she photographed and sketched the biface, then crouched down and carefully put the stone back where she'd found it. The archaeologists do not remove artifacts during survey work. I asked Baker, "Aren't you worried that something will happen if you just leave it lying around? What if someone steals it?"

"This is the best warehouse in the world," he said. "These have been here thousands of years and no one's fucked with 'em yet. It takes big bucks to get up here. Plus it's illegal to take stuff from federal land. It already has an owner: you and me."

As we walked off the bluff, I asked Baker, "Is this an interesting site? Is it old?"

"There's nothing diagnostic," he said. "All I can tell you is that some person was up here sometime in the past, banging the hell out of these rocks."