The “Oak” fire and the “Washburn” fire had very different outcomes. Why?
By Alex Wigglesworth, LA Times
(PLACERVILLE, CALIFORNIA) Aug 2, 2022 — The two fires started just 17 miles apart in the rugged terrain of California’s western Sierra Nevada — but their outcomes couldn’t have been more different.
The Washburn fire, which ignited July 7 along a forested trail in Yosemite National Park, was nearly contained, with no damage to structures or to the famed Mariposa Grove of giant sequoias.
But the Oak fire, which sparked almost two weeks later in the foothills near Midpines, confounded firefighters as it exploded to four times the size of Washburn and forced thousands to flee as it destroyed at least 106 homes. At times, the wildfire’s smoke plume could be seen from space.
Why was one fire so much more destructive?
Experts attribute the difference to variations in weather, vegetation and topography. The management history of each landscape also played a role: Yosemite boasts decades of active stewardship, including prescribed burns, while areas outside the park bear a legacy of industrial logging and fire suppression.
The Washburn fire started along a trail on the edge of the Mariposa Grove, just downhill from the road used by shuttle buses to ferry tourists from a parking lot.
Since vegetation along the trail was dense, and flames travel more quickly uphill, officials worried that the fire would grow hotter, gain speed and slam into the sequoia grove, said Yosemite Fire Chief Dan Buckley. That could result in a high-severity crown fire similar to those that have destroyed an estimated 20% of the world’s population of the ancient giants since 2020, he said.
But luck was on the side of the fire officials: Two Yosemite battalion chiefs were teaching a chainsaw class to a sizable contingent of firefighters in the nearby Wawona area and were able to quickly respond, along with a water tender, two engines and the park’s water-dropping helicopter […]
— OFFICIAL STATEMENTS BY FIRE AGENCIES —
WASHBURN FIRE: 4,886 Acres.
Fuels Involved: Very heavy accumulations of available dead surface fuels with ample snags, downed logs, and fuel concentrations in an old growth forest landscape. Representative fuels include multi-species conifer timber with an understory of young conifer and shrubs. Very deep duff and accumulation of timber litter (branchwood and needles) dominate the forest floor. Recent large fire scars in the area include woody fuels and recent shrub growth. Live fuels (shrubs/brush) are seasonally moist and are providing limited intensity and spread.
OAK FIRE: 19,244 Acres.
Fuels Involved: Timber, Brush, Understory Litter.
193 Structures Destroyed
[Residential, Commercial and Other]
Consider the Source – Alex Wigglesworth is an environment reporter who covers wildfires for the Los Angeles Times. Before joining the L. A. Times, she was a general assignment reporter for the Philadelphia Inquirer, Daily News and Philly.com. A Philadelphia native, she graduated from the University of Pennsylvania with a degree in medical anthropology and global health. She currently lives in Inglewood.