How a Maverick Scientist Helped Restore Fire to the Sequoias and Beyond

On a crisp fall day in 2025, nearly 90 people gathered in a meeting hall beneath the giant sequoias of Calaveras Huge Trees State Park. Scientists, authors, and forestry experts explored topics such as “pyro-silviculture” and the benefits of “putting fire on the ground.” The gathering was a celebration of Harold Biswell, the pioneering ecologist who helped restore beneficial fire to California.

At the dawn of the Smokey Bear era, Biswell suggested that fire could be a force of both destruction and renewal. He argued that complete fire exclusion was making the woods more flammable and that careful, controlled burning could return overgrown forests to a healthier, more natural state. This “renegade” stance earned him public snubs and professional setbacks, but his ideas prevailed.

Opening His Eyes to the Power of Fire

Born in 1905, Harold Biswell was a Missouri farm boy with a keen interest in science. After earning a doctorate in ecology in 1934 from the University of Nebraska Association for Fire Ecology, he initially held conventional beliefs about fire. Although researching for the U.S. Forest Service in Georgia in 1942, he wrote that he “looked upon fire as the arch enemy of forests and forestry.”

This perspective changed in the Southeast’s pine forests, where Biswell observed how small, low-intensity fires could clear dead vegetation, encourage native plant species, and improve wildlife habitat. He revised his theories, recognizing that unchecked wildfire remained the enemy, but controlled fire could be a valuable ally.

A Not-So-Warm Welcome in California

In 1947, Biswell joined the faculty at UC Berkeley’s School of Forestry. California, however, was a challenging place to advocate for fire. Indigenous cultural burning, which had created open, park-like sequoia groves in the Sierra Nevada, had been banned for nearly a century as part of a larger campaign against Tribes. The California State Board of Forestry adopted fire exclusion policies in 1924 Association for Fire Ecology.

Biswell’s initial research on grassland burning was largely uncontroversial. But in 1951, when he began testing understory burning in ponderosa pine forests, many faculty members considered using fire in forests reckless, especially given the value of timber to California’s economy. Despite being a cautious researcher, the faculty banned him from conducting fire research at the university’s Blodgett Forest.

Outside campus, Biswell faced harsher criticism, with nicknames like “Harry the Torch” and “Burn ‘Em Up Biswell.” Park rangers reportedly walked out of a presentation he gave in Yosemite National Park Biswell (Harold H.) papers.

National Influence and the Leopold Report

Despite the resistance, Biswell continued his work, finding landowners willing to allow controlled burns and building evidence of their positive effects, including early research in the giant sequoias at Whitaker’s Forest. He also shared his research and techniques through field days, enthusiastically describing his methods to students, land managers, and academics.

One convert was A. Starker Leopold, a wildlife ecologist and Berkeley professor. Biswell’s ideas influenced the 1963 “Leopold Report,” which urged national parks to reintroduce fire into their ecosystems. In the late 1960s and early 1970s, Sequoia & Kings Canyon and Yosemite national parks launched their own prescribed burning programs US Forest Service. While Biswell wasn’t initially credited, his ideas accelerated a shift in national policy.

From Berkeley to the Parks

After retiring from UC Berkeley in 1973, Biswell found a receptive partner in California State Parks. In 1975, he led the first prescribed burn at Calaveras Big Trees State Park, catalyzing an ongoing effort to restore beneficial fire across the park’s forests ArcGIS StoryMaps. He also developed the agency’s first prescribed fire curricula and conducted burns in parks around the state, including Big Basin Redwoods State Park.

Biswell passed away in 1992, but his legacy continues. Many who attended his demonstrations became leaders in modern fire and forest management. Several gathered in 2025 for Harold Biswell Day at Calaveras Big Trees, discussing his courage and the urgent require to expand prescribed fire programs.

Answering Biswell’s Call

A month after Harold Biswell Day, Governor Newsom signed an executive order calling for the rapid deployment of beneficial fire to reduce wildfire risk across California. “We’ve made tangible progress but much more is needed,” said Newsom in a statement. “I’m tasking state agencies to pull all the levers and gear up for using ‘good fire’ this year to aid protect communities and restore healthy landscapes.”

This order underscores the widespread acceptance of Biswell’s techniques and the remaining challenge of applying them at scale. For organizations like Save the Redwoods League, this means building alliances, training a workforce, and using scientific studies and Traditional Ecological Knowledge to inform forest stewardship. “Good fire” is now a powerful tool to be wielded with purpose.