In the vast forests and open spaces of Minnesota, finding missing people can be expensive and time consuming.
When someone is lost in the north woods, searching for them often requires airplanes, helicopters and dozens of people.
To make such searches more efficient, White Earth tribal conservation officers are learning an ancient skill called man tracking.
Learning to follow the tracks people leave behind can save time and money, said Al Fox, the tribe's chief conservation officer. But to do so, searchers must crouch low to the ground to read signs an untrained observer would miss, like footprints buried beneath pine needles and leaves.
"If you get down in here you can actually see little details," Fox said of clues left in the forest during a training exercise earlier this month. "Like right here. See that imprint right there? That would be the heel strike. That would be the back of the boot."
Slowly following the trail for several yards through the woods, Fox said tracks left on the forest floor, even old ones, stay visible to the trained eye.
"You'll see things like broken twigs," he said. "These pine needles, when they're this dry and you step on them, they're going to crack, they're going to break."
Grass bruises when it's stepped on. Moss bends underfoot leaving prints much like you'd see on a thick carpet.
A short way down the trail, three people are studying the ground. They're trying to follow a two-day-old track created for a training exercise.
One of the students is Steve Dahlberg, who runs extension programs at the tribal college.
Dahlberg teaches a class in tracking animals. But he said tracking humans is much more intense.
"You know you're training for something really important," he said. "If you're out on wildlife sign and you lose a trail, oh well, you go on and find something else. But here there's a lot more at stake so you've got to be able to find that next track. That's what makes it challenging."
"It's going to be a long battle for us to show that this is more than just a hobby."
Dahlberg and several of the White Earth Conservation officers are studying with a retired border patrol agent who trains trackers across the country. Dahlberg said tracking is much more effective than the usual practice of lining up searchers and sending them into the woods.
"Somebody could be on the ground between two searchers and they don't see them and the person doesn't alert them that they're there, and they can go right past, literally almost step on them and not see," he said. "It's much more effective to actually follow the person than just flail around in the woods and hope you stumble on to them."
None of these trackers studying man tracking consider themselves experts yet. But the conservation officers say they use the skills often. Al Fox has helped find a woman lost in the woods.
Conservation officer Sheila LaFriniere recalls a situation when police noted an abandoned car along the road near a lake. She said no one paid much attention until a fellow conservation officer and trained tracker stopped to investigate.
"He was able to see there's tracks going in but there's no tracks coming back to the vehicle. So there's something not right. He's still here somewhere," LaFriniere said. "When they broadened the search, he was still on the lake and he was dead."
Fox is convinced trained trackers could save lives, and help solve crimes. But so far, he said, most law enforcement agencies are skeptical.
Fox thinks that's because they haven't seen trackers work, and because it takes a big time investment to become an expert tracker.
"This is something new that we're bringing to their attention," he said. "It's going to be a long battle for us to show that this is more than just a hobby."
Fox plans to organize more training sessions next spring for anyone interested in learning to track people.