In mid-July 1974, a bolt of lightning struck a tree in a remote area of Wyomings Grand Teton National Park, igniting a blaze that burned for three months and marked a major shift in federal wildfire policy.

Rather than racing to stamp out the flames, park officials decided to monitor the fire. Decades of suppressing fires, natural and human-caused alike, had left Americas forests overgrown and prone to extreme conflagrations. Emerging research showed that allowing nature to run its course would benefit forest health.

The National Park Service had revised its wildfire management policy a few years earlier, and the Forest Service followed suit that year. The Waterfall Canyon Fire in Grand Teton was one of the first large fires officials let run its course inside a national park, and it torched some 3,700 acres before rain and snow finally extinguished it that fall.

An October New York Times article , Rangers Refute Smokey Bear and Let Forest Fire Spread, captured locals frustrations with the controversial new policy, as the sight of smoke-filled skies and smoldering old-growth trees prompted accusations that the park was taking a scorched earth approach to fire management. Hundreds signed a petition urging the federal agency to conduct its experiments in more isolated areas.

Officials said critics threatened to derail a science-based policy. Weve had nearly 200 years in this country of saying fire is bad, Tony Bevinetto, the parks information officer, reportedly told visitors at the time. Its neither bad nor good its natural.

Nearly half a century later, wildfire experts are fighting the same fight. And the person perhaps most responsible for Americans reflexive anti-fire sentiment isnt a person at all, but a cartoon bear: Smokey, the Forest Services lovable icon of fire prevention.