A homeless man was arrested on arson charges Sunday, accused of sparking the blaze.By CBSLA Staff

LOS ANGELES (CBSLA) – The arson-sparked Ranch 2 Fire burning in the Angeles National Forest north of Azusa grew to over 3,000-acres, officials reported Monday morning, with the ongoing heat wave expected to continue to pose challenges to firefighters.

A plume of smoke rises from the Ranch 2 Fire on Aug. 15, 2020, as seen from Azusa, Calif. (Getty Images)

As of 10 a.m., the fire had burned 3,050 acres and was only 19% contained. The fire spread to the Pine Mountain Peak Sunday, the U.S. Forest Service reported.

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The more than 450 firefighters assigned to the blaze were facing triple-digit temperatures and possible thunderstorms Monday. Making the firefight more difficult was the rugged terrain the blaze was burning in.

All evacuation orders were lifted Friday for the Mountain Cove community. No homes have been destroyed in the fire.

“Firefighters continue to mop up and backhaul trash and equipment on the southern boundary near the Mountain Cove community and there is little heat in this area,” USFS said in a news release Monday.

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The heat wave that has enveloped the region is expected to last into Wednesday at the earliest.

On Sunday, a homeless man suspected of sparking the fire was arrested on arson charges. A suspect in the Ranch 2 Fire in Azusa was taken into custody on Sunday afternoon. 36-year-old Osmin Palencia was known to camp in the Azusa Canyon Riverbed.

The Ranch 2 Fire was reported about 2:45 p.m. Thursday near North San Gabriel Canyon Road and North Ranch Road.

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Highway 39 remains shut down in the area.