SMOKESHOW
Published in the September 13, 2025 edition.
This week, the mountains that usually frame the Eastern Sierra skyline disappeared into a gray wall of haze, and the sun shrank to a dim orange pinprick. Across the region, people bemoaned the familiar campfire smell that clung to their clothes.
But the smoke was more than just a nuisance. Air quality dipped into “very unhealthy” and even “hazardous” zones at times throughout the week, prompting an Air Quality Health Advisory for Mono and Inyo counties.
The source of the smoke, the Garnet Fire, started August 24 and had burned more than 57,000 acres with 15% containment as of Thursday morning. The U.S. Forest Service estimates full containment by September 30.
So, how long will the smoke last? The honest answer: no one knows.
Predicting how long or how pervasive a fire’s smoke will be is tricky, said Kim Mitchell, Senior Research Systems Analyst with the Great Basin Unified Air Pollution Control District.
“If you think it’s hard to predict weather, try predicting weather and fire behavior,” she said. “We have people who have been experts in weather for decades and decades, and still get it wrong.”
The district does not have a forecaster on staff, and Air Resource Advisors — technical specialists trained to assess smoke from wildland fires — only issue predictions up to three days out.
That said, there are a few constants, Mitchell explained. The region’s topography, for example, plays a huge role in how smoke moves.
“Smoke flows like water, and in Mammoth, the same passes that funnel winter storms for skiing also channel smoke,” Mitchell said. “That’s why Mammoth often gets hit harder than its neighboring communities.”
Smoke is also heavily influenced by fire behavior: how fast the flames grow, its direction, and what kind of fuel is burning. The Garnet Fire, for example, is consuming heavy, beetle-killed timber, meaning there is abundant fuel. The fire is burning fast and producing thick smoke.
Weather, too, plays a decisive role. Late this week, higher humidity slowed fire growth, easing smoke in the north. Wind proved just as critical: on Wednesday, northerly gusts pushed smoke south and away from Mammoth. But by Thursday morning, the winds had shifted back toward Mammoth.
Sometimes smoke stays high in the atmosphere, Mitchell noted, so skies look bad but ground-level air quality remains tolerable. Other times, it drops and lingers at the surface, where people feel it most.
Smoke events are becoming more common in the Eastern Sierra, Mitchell said. In the past decade, she’s seen an increase.
In 2020, for example, Mammoth endured three solid weeks of “hazardous” or “very unhealthy” air, including 12 hazardous days in September alone.
The region saw three relatively smoke-free summers from 2022–2024, but 2025 is shaping up to be the second worst in the last decade.
In light of this, Mitchell suggests people take precautions to protect themselves from smoke:
Avoid smoky periods. Track conditions and plan activities around the worst air quality.
Reduce activity. Limiting exertion lowers the amount of pollutants you inhale.
Protect sensitive groups. Children, pregnant women, older adults, outdoor workers, and those with chronic illnesses are more vulnerable.
Keep indoor air clean. Close windows and doors, turn off swamp coolers, and run air conditioners on recirculation if possible. If you cannot keep indoor air clean or it becomes too hot, consider relocating to an area with better air quality.
Don’t rely on cloth masks. Bandanas, cloth, or dust masks offer no protection. Properly fitted N95 respirators provide some protection, though they can be difficult to breathe through.
Mono County Public Health is also operating clean air centers across the county, a new measure this year to give residents with poor home air filtration a place to get relief.
For shelter locations and updates, see monocounty.ca.gov. For current air quality conditions, advisories, and guidance, including how to use visibility to gauge air quality, visit gbuapcd.org.
