The fire is 95% contained, officials said.
WASHINGTON TWP., New Jersey (WPVI) -- The wildfire at Wharton State Forest in Burlington County, New Jersey, now called the Mullica River Fire, is 95% contained.
The New Jersey Forest Fire Service said Tuesday morning that crews continue to make "substantial progress in containing the wildfire."
The fire has reached 13,500 acres in size, officials said. It is now the largest fire in the state since 2007.
As firefighters made more progress on day three, they are also learning more about its origin.
"We found an area where the fire started," said Bill Donnelly, assistant State Fire Warden for the New Jersey Forest Fire Service. "There appeared to be a campfire in that area. So with that we're going to follow up and see what we can come up with."
Officials said the fire spread over 20 square miles, so large it was visible from weather satellites on Monday.
An image released by the National Oceanic and Atmospheric Administration shows the fire and the plume of smoke spreading across New Jersey.
Paradise Lakes Campground in Hammonton was among the places threatened.
Just as a music festival was cleaning up there on Sunday, organizers and campers were told to get out.
"Around 5 o'clock the fire marshal called and said hey you have to evacuate," said Scott Miller, who owns the campground.
"The smoke cloud all of a sudden got huge around 5 to 6 p.m., and then the land owner rushed over here in his truck and came shouting, 'We need you all out of here.' He was really worried," said Jeremy Savo, co-director and founder of Beardfest music festival.
The fire stretches through Washington, Shamong, Hammonton and Mullica townships.
On Tuesday morning, the fire service set small fires to burn the vegetation around a one-room school house from the 1860's in an effort to protect the historic structure.
"All these homes around here are from the 17th century, so they're the last remnants of that revolutionary war era," said Tom Gerber, Section Forest Fire Warden and Operations Chief for the Mullica River Fire. "There's some dead and downed trees that need to be consumed by the fire and that'll lessen the chance of something happening when all this fire equipment's not around."
Full containment of the fire is expected by Wednesday.
The impacts of the wildfire could be felt at the Jersey shore.
"I thought it was fog at first, but then I started to notice the smell and I knew it wasn't fog," said Alicia Washington of Atlantic City.
Residents are urged to take proper precautions.
"It's not a time to take any chances with the amount of smoke that we've all been seeing," said Dr. Amit Borah, an interventional pulmonologist at AtlantiCare Regional Medical Center. "Stay away from the heat, that thermal injury, that hot, hot air, that hot, hot smoke -- that's the thing that will do even someone with healthy lungs in."
No injuries have been reported and no homes are in danger, but 18 structures were threatened, including a blueberry farm and the Paradise Lake Campground where some were evacuated."
"It's been a really long time since I actually saw fire whirls on a fire, and yesterday I saw several of them. That's extreme fire intensity," said McLaughlin.
As of Tuesday, Route 206 and Route 542 have reopened.
Batsto Village, Atsion Recreation Area and all associated hiking and mountain bike trails remain closed to visitors.
The Mullica River Campground and Lower Forge Campground are closed.
Kayak and canoe launching along the Mullica River is closed from the Atsion Recreation Area to Batsto Village.
These closures will remain in effect until further notice.
Pinelands Adventures has suspended kayak and canoe trips.
There are no reported injuries.
"Motorists traveling in the area should remain cautious of smoke and watch for firefighters and fire vehicles that may be working on nearby roadways. Smoke impacts will remain elevated into the evening hours as winds diminish, and partial cloud cover moves over the area," the forest service said.