Riley Smith is a big-tree hunter. A documenter of what he calls the silent witnesses of history.

The Plymouth college student will log hundreds of miles this summer on foot, in a canoe and behind the wheel, trying to give voice to the state's largest native tree species. His summer travels could take Smith — armed with two range finders, a 100-foot tape measure, a GPS and assorted other gear — to a green space near a suburban strip mall or the remote reaches of the Boundary Waters Canoe Area Wilderness. His goal: hunt, find and measure a record big tree and have it placed on the state's Big Tree Registry.

"I've always been fascinated by trees. They live in one place, sometimes for centuries. They watch as generation after generation pass by and as communities grow and change around them," said Smith, 18, an urban forestry major at the University of Wisconsin-Stevens Point. "That intrigues me. Being a big-tree hunter allows me to be a part of Minnesota's evolving natural history. That intrigues me, too."

This month, the Minnesota Department of Natural Resources relaunched its Big Tree Registry program. The registry began in 1962. It was mothballed two years ago, owing to a lack of resources. "We just didn't have the staff to administer the program and not enough foresters to verify measurements," said Jennifer Teegarden, DNR forestry outreach specialist. "We now have a staff member to administer the program and an increase in the division of forestry's general funds allowed us to hire more foresters."

The program's overriding goal, Teegarden said, is to enlist as many Riley Smiths as possible to document the state's biggest trees. Her hope is the emphasis will encourage a greater appreciation for trees and their environment. Minnesota has 52 native tree species scattered across the state. A "big tree" nominee is judged on a scoring formula of three measurements: circumference, height and crown spread. An application must be filled out to nominate a tree for the registry; a DNR forester verifies nominees.

"Trees are an important part of Minnesota and its history," Teegarden said. "The large pines and hardwoods brought pioneers to Minnesota. Although most of the large trees in Minnesota were cut down in the late 1800s and 1900s, some big trees survived. So it's a rare opportunity to see one of the state's largest native trees."

Teegarden said the program also helps the public with tree identification and measuring. "The program celebrates our natural resources, and the best part about it is that anyone can do it," said Teegarden. "I've always had a passion for trees, particularly caring for urban trees. From the time I could climb, I was in a tree. So I believe it's important to expose children at a young age to nature and trees to develop future natural resource stewards."

Early questions

Smith started hunting and measuring trees when he was in eighth grade, but his fascination started much earlier. He said his parents tell stories about a curious youngster worried about trees. "There was the time when I was 3 or 4 when my parents came outside and found me crying," said Smith. "Apparently, I was crying because the neighbors were cutting down their trees."

On trips to the Boundary Waters as a boy, Smith said, he would ask his father countless questions about trees. About how big and old they could get. About blow downs. About fire and its effect on forests. "My interest in trees was always there," Smith said. "I've always asked a lot of questions."

As a forestry student, he can now answer his own questions. For example, what makes a big tree? "It all depends on the species, of course, but it comes down to the big factors of nutrients, sunlight, soil, water, competition for those things, and weather and outside influences," Smith said. "A sugar maple, for instance, can spend the majority of its life in the understory before growing into the canopy. A red cedar, on the other hand, is intolerant of shade. It just all depends."

Smith said he registered his first tree with the DNR in 2010 — a black willow found in Brooklyn Park. It measured roughly 18 feet in circumference. "It wasn't in some pristine woodland. … I found it about 30 feet from a parking lot in an incredibly polluted wetland," said Smith, adding that his largest tree also is a black willow with a girth of 26 feet. He found it in Elm Creek Park Reserve in Maple Grove. "There was a learning curve for me early on because I was learning the species as I went along and got some wrong originally. It takes time. The great thing about hunting big trees is that you can find one anywhere. You can stumble on a huge tree at a shopping center."

Smith's favorite tree is the tamarack, which he says is the only deciduous conifer native to Minnesota. Minnesota is also home to the nation's largest tamarack, found in 2004 on private land in Crow Wing County. It's 71 feet tall, with a 133-inch circumference and a 60-foot crown spread. "There are so many features to the species," he said. "They're absolutely beautiful in the fall … and one of its natural habitats — peat bog — is almost alien in nature because it's so different from any other ecosystem."

"Sense of wonder"

When Smith finishes college, his career goal isn't so surprising. "My perfect job would probably be something like a city forester or possibly a forester for an urban park district," he said. "I like the idea of managing the city forest for a community."

In his spare time, he'll be hunting for a tree that makes Minnesota's Big Tree Registry.

"There is definitely a sense of awe and wonder for me, especially if the tree or woods is really special," he said. "Part of the reason is because something so massive as a big tree commands respect. When you stretch your neck and look left and right but still cannot see the whole tree, it is a magical experience for me."

Tori J. McCormick is a freelance writer from Prior Lake. Reach him at torimccormick33@gmail.com