AZUSA, Calif. (NewsNation Now) — The fast-moving Bobcat Fire has grown to more than 4,800 acres as it continued to burn out of control in the Angeles National Forest in the San Gabriel Mountains northeast of Los Angeles.
The blaze erupted around 12:20 p.m. PT Sunday, according to the federal InciWeb site. Containment remains at 0%.
“The fire could experience explosive growth,” the Crescenta Valley sheriff’s station said.
The fire threatens to destroy Mount Wilson’s seismic station, which is operated by Caltech and has recorded every important earthquake in the state for the past century, according to renowned seismologist Lucy Jones.
Cal Fire ordered an evacuation of the staff Monday morning, according to a Facebook post on the observatory’s page.
In an unprecedented move, the Forest Service is closing down eight sprawling forests in California as of 5 p.m. PT Monday — including the Angeles National Forest.
All day-use and camping areas along Angeles Crest Highway between Mount Wilson Road and Islip Saddle are under mandatory evacuation, and the twisting highway is also closed. Highway 39 has also been shut down at San Gabriel Canyon Road.
Mount Wilson Road, which leads to the observatory, is also shut down.
A temporary flight restriction is in place over the area as firefighters attack the flames by ground and air.
With the fire spreading smoke and ash over the region, the South Coast Air Quality Management District warned of unhealthy air quality in the San Gabriel Mountains, eastern San Gabriel Valley and Pomona-Walnut Valley.
Fire crews also face another day of challenging weather conditions, after Sunday saw temperatures that didn’t drop below 90 degrees in foothill and lower mountain areas.
Highs in lower mountain and foothill areas in L.A. County are forecast to be between 103 and 115 degrees on Monday, with the region overall seeing a slight dip in temperatures from the previous day’s historic heat, according to the National Weather Service.
The cause of the blaze remains under investigation.
NewsNation affiliate KTLA contributed to this report.