IN THE SPRING AND EARLY SUMMER OF 2015, the southern Northwest Territories were gripped with morel fever. The previous summer’s unprecedented wild fires had created the perfect conditions for a bumper crop of the mushrooms, which are a delicacy prized in high-end kitchens. The fires had burned right along the edges of Highway 3—the major artery that connects the region to the rest of Canada—which meant easy pickings. The territorial government predicted a $10 million boost to the economy.

Hundreds of pickers—locals and imports from the Yukon, British Columbia and even France—descended on the highway, anticipating fortunes to be found in the boreal forest. By June, though, many were not faring well. Global market trends had halved morel prices from their 2014 peak. Drought conditions had delayed the crop. And many pickers were simply inexperienced, now straining to recoup their travel costs. Still, the foragers ...