COLORADO SPRINGS, Colorado—It’s the unpredictability that hooked cartographer Matt Dooley on the concept of making maps with gunpowder.

“It's impossible to control,” he says. “So it's an opportunity to let go, relax, and be open to surprises.”

After a decade as a professor at the University of Wisconsin-River Falls, Dooley had fallen into a rut. “Plain-Jane, vanilla cartography” is how he describes his work at the time. And then one day, in a campus courtyard near his office, he saw some art students experimenting with gunpowder and paper, igniting their work.

“I was instantly mesmerized,” Dooley says. He had seen a documentary featuring gunpowder art by Chinese artist Cai Guo-Qiang, but it hadn’t occurred to him to try it himself until