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Bobcat Fire: Blaze Grows To Over 38K Acres; Serious Threat To Mt. Wilson

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This story is no longer being updated. Follow our coverage of the Bobcat Fire for Tuesday, Sept. 15>>
Jump to: Basics | Evacuations | Weather Conditions | About Mt. Wilson | Additional Resources

The Bobcat Fire continues to grow in the Angeles National Forest, causing evacuations and threatening foothill communities.

View from Mt. Wilson tonight from cameras operated. (Courtesy HPWREN via UC San Diego )
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It's also getting perilously close to Mt. Wilson observatory, where firefighters have begun actively defending the building. "

Fire officials warned in the evening briefing that resources to fight the fire were limited, which contributed to the fire's growth "outpacing containment."

Authorities cautioned that low humidity and warm temperatures overnight will allow the fire to "burn actively through the night."

Earlier in the afternoon, Angeles National Forest tweeted that the fire was burning on the ridge line above the east side of Little Santa Anita Canyon, and that "air operations were actively making drops".

To the east, Monrovia city officials warned that the fire was moving into Spanish Canyon, and that extra aircraft were being brought in help.

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"In addition to the aircraft, residents of Monrovia, Duarte and Bradbury will see an increase in smoke, flames and firefighting activities during this time."

They added that the fire will get closer to the foothill communities as the evening progresses.

"Please know, the fire is beginning at a point high up the mountain but will be backing downward slowly and in a controlled manner."

Here's what we know about the fire so far today.


  • Acreage: 38,299 acres
  • Containment: 3%
  • Resources deployed: 1,091 firefighters
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The blaze erupted last Sunday near the Cogswell Dam and then spread rapidly amid an intense, record-breaking heat wave, prompting evacuation orders for Mt. Wilson Observatory. The cause is under investigation.
Firefighters continue to work in steep difficult terrain with help from helicopters and planes. Crews are hoping to take advantage of low winds forecasted for the next few days to build some containment lines around the flames.

The focus today has been protecting foothill communities and Mt. Wilson, U.S. Forest Service officials tweeted this morning. Officials report the the fire has crossed to the west side of Santa Anita Canyon and continues to grow and move toward Mt. Wilson and Mt. Harvard.

Residents of dozens of homes in the Sierra Madre / Arcadia area were ordered to evacuate Sunday, but firefighters have been able to keep the fire away from houses so far, officials say.

Angeles National Forest officials are hosting a virtual meeting on Zoom at 6:30 p.m. this evening to provide updates on the fire. You can join the meeting here.

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  • The Angeles National Forest β€” along with every other national forest in the state β€” has been closed
  • State Route 39 is closed at Old Gabriel Canyon Road to State Route 2
  • State Route 2 is closed from Upper Big Tujunga Canyon Road to Big Pines
  • Upper Big Tujunga Canyon Road
  • Mt. Wilson Road
  • Glendora Mountain Road
  • Glendora Ridge Road


Mel Cohen removes family photos from his home on Highland Vista during evacuations as the Bobcat Fire approaches the foothill community of Arcadia. (Brian Feinzimer/LAist)


On Sunday morning, the city of Arcadia issued an evacuation order for all residents who live north of Elkins Avenue and east of Santa Anita Avenue. That area includes some homes in the adjacent city of Sierra Madre. That order will remain in place Monday night, Arcadia city officials announced in the afternoon.

An evacuation order is also in effect for Camp Williams, located just east of the burn zone in the Angeles National Forest.


Evacuation warnings remain in effect for the following foothill cities and communities:

  • Monrovia
  • Arcadia (excluding the neighborhood under mandatory evacuation orders)
  • Sierra Madre (except the 32 homes under mandatory evacuation orders)
  • Bradbury
  • Duarte
  • Pasadena
  • Altadena

"Residents should have evacuation plans in place, organize their emergency evacuation supplies, and have essential evacuation personal belongings easily accessible," U.S. Forest Service officials wrote on the fire incident page. "Vehicles should be fully fueled, facing out in their driveways and ready to leave."

People watch as the Bobcat Fire burns on hillsides behind homes in Arcadia, on Sept. 13, 2020. The blaze prompted mandatory evacuations for residents of several communities. (Frederic J. Brown/AFP via Getty Images)


A Red Cross Evacuation Center was re-established at Santa Anita Park, 285 W. Huntington Drive (entry at Gate 5).

L.A. County officials said a shelter site for horses has been established at the Pomona Fairplex (entry at Gate 12).


The South Coast Air Quality Management District has extended a smoke advisory to Tuesday as unhealthy air continues to blanket much of the L.A. Basin and Inland Empire. It's not just local fires though; smoke is also making its way to us from wildfires in Northern California, Oregon and Washington.

Smoke is expected to linger in the basin and valley areas overnight, but officials say it will continue to clear up through tomorrow afternoon, thanks to south-blowing winds.

Look up the latest air quality info for your area at


The Mount Wilson Observatory houses 18 telescopes, many of which were used to make some of the greatest astronomical discoveries of the last century. They include the 100 inch Hooker telescope that Edwin Hubble used in the 1920s to prove that our universe is still expanding.

Observatory Director Tom Meneghini said he's afraid they could be seriously impacted if the fire gets close enough.

β€œThe heat can do irreparable damage. Our two big telescopes are historically significant and irreplaceable,οΏ½? Meneghini said.

However, he said fires have gotten close before and the decades-old firefighting setup at the Observatory is ready to be used again. "We have an inground system of hoses and pumps," he said.

"We have half a million gallons of water ready to pump so that’s all been prepared for any fire professional to come in and take over."

>The fire also threatens a seismic station that has recorded earthquake activity for 100 years, seismologist Lucy Jones said via Twitter.

Numerous television and radio stations have transmitters in the area, including our newsroom which broadcasts on the radio at 89.3 KPCC.


This is a developing story. We fact check everything and rely only on information from credible sources (think fire, police, government officials and reporters on the ground). Sometimes, however, we make mistakes and/or initial reports turn out to be wrong. In all cases, we strive to bring you the most accurate information in real time and will update this story as new information becomes available.


For the latest information straight from local emergency officials, check the following websites and social media accounts:



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