MILFORD, Lassen County (CBS SF) — Gusty winds whistled across the southeastern edge of the massive Dixie Fire late Wednesday, pushing the wall of flames several miles toward Highway 395 as firefighters braced to once again engage the blaze in the treacherous terrain of the escarpment.

Cal Fire Chief Don Watt, the fire behavior specialist, said the flames, fueled by winds, terrain and drought-dried vegetation, gained speed all day long.

READ MORE: Fmr. Pinole Police Officer Allegedly Videotaped Himself Having Sex With Minor

“The big concern today was on the Highway 395 corridor, it is a very windy location that tends to stay windy longer than what we see on the northern part,” Watt said at a Wednesday night update. “So that fire made a pretty good progression today. It traveled several miles this afternoon and continues to burn actively.”

The fire, which ignited on July 14, possibly sparked by PG&E equipment, grew to 859,457 acres over the past two months and was 55% contained as of Wednesday but it continued raging to the southeast and along the northern edge in the woods and wilderness of the Lassen Volcanic National Park. It has burned at least 696 homes and ravaged the communities of Greenville and Canyondam.

Wednesday’s run brought the blaze once again to the edge of the escarpment — a rise of land stretching for miles where winds swirl and the terrain is very challenging. It’s a region that has become all too familiar to firefighters.

More than a week ago, firefighters battled the flames further north on the escarpment to successfully keep the fire out of Milford.

Miles to the south, they staged a firefight with the Beckwourth Complex fire, which was ignited by lightning strikes on July 3. Crews succeeded in totally containing the fire on Wednesday after it burned 105,670 acres and destroyed much of the town of Doyle.

READ MORE: UPDATE: Woman Accused of Starting Fawn Fire Was Boiling Bear Urine to Drink

“It’s almost to the escarpment now,” said Cal Fire West Operations Chief Tony Brownell. “We’ve move a lot of engines and personnel around, we are down around 395, concentrating on structure protection. So when it does come off that hill we are going to be there to catch it and keep it out of structures the best we can.”

The wall of fire approaching the escarpment began as two spots fires that merged along the then southern edge of the blaze in the Genesee Valley last week. The flames advanced along Grizzly Ridge and firefighters were able to keep it away from Quincy, Greenhorn and Cromberg.

The southern edge of the blaze was also approaching the Davis Lake area.

Along the northern edge, spot fires continued to challenge firefighters in and around the national park.

“The northeast side of the fire, that’s where it’s given us problems with the last wind event we’ve had,” Watt said. “The fire was pushing against it, trying to push it out. We had spotting issues near the Hall Road. It is spotting over the top, meaning embers are going over our control lines and causing new fires.”

MORE NEWS: SF Police Arrest 2 Men Who Allegedly Shot Woman Who Refused To Give Them Her Camera

DIXIE FIRE: