Could beavers be the secret to winning the fight against wildfires?

The East Troublesome fire erupted on October 21, 2020, whipped by strong winds and fueled by drought-parched forests. The fire roared through northern Colorado's spruce and fir woods; it leaped roads and rivers and the Continental Divide, scaling mountain passes above tree line. It incinerated historic buildings in Rocky Mountain National Park and homes in Grand County, killing two people. Ultimately, it torched nearly 200,000 acres, making it the second largest fire in Colorado's history.

In the end, just about the only thing the East Troublesome didn't consume was beaver ponds.

This was not entirely surprising. Beavers, of course, build dams that store water-and water, as you may know, doesn't burn. But the benefit the semiaquatic rodents provide goes further than that. In a study published weeks before the East Troublesome blew up, Emily Fairfax, an ecohydrologist now at the University of Minnesota, found that beaver ponds and canals irrigate the landscape so thoroughly that they turn crisp, flammable plants into lush, fireproof ones, forming green refuges in which wildlife and livestock can retreat. In a nod to another firefighting icon, Fairfax and her co-author titled their paper "Smokey the Beaver."

Fairfax studied five fires between 2000 and 2018 to reach her conclusions. But the East Troublesome was far bigger than most of those blazes-and a harbinger of the kind of conflagration we're seeing more and more. Although fire has long been a natural force of regeneration on North American landscapes, the so-called megafires that plague the ever drier West are a different matter, stoked by climate change into explosive infernos that burn so big and hot that ecosystems don't always readily recover. Fairfax doubted whether beavers could still fireproof large tracts of the landscape under those conditions. But when she visited the charred forests left behind by the East Troublesome and one other megafire, she discovered that the oases beavers created with their ponds had endured. "There are entire rivers that are basically unaffected by the fire, because it's just beaver dams the whole way," she said. "Everything is full of life: The reeds are growing; the pine needles are still on the trees." The ponds aren't merely helpful before a fire-they can also protect ecosystems from the effects that come right after a blaze, capturing the ash and debris that run off hillslopes and shielding downstream fish and drinking water. In a 2024 paper describing their findings, Fairfax and her collaborators concluded that beavers "can be part of a comprehensive fire-mitigation strategy."

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