A raging wildfire in South Jersey's vast Wharton State Forest had spread to more than 1,000 acres last night as firefighters struggled to contain it, state officials said.
Flames from the wildfire and containment fires were expected to consume 3,000 acres.
No injuries had been reported last night and no homes had been threatened.
A four-mile stretch of Route 206 south of Tuckerton Road - about a mile from the hot spot - was closed to traffic at 7 p.m. because of heavy smoke and safety concerns, said Darlene Yuhas, state Department of Environmental Protection spokeswoman.
As part of the containment effort, backfires were set to burn off brush and vegetation, said Steve Maurer, assistant state fire warden.
The fire, in Burlington and Atlantic Counties, was about five miles north and west of Batsto. The historic Pine Barrens village's 33 buildings, including mills, homes and a general store, were not in danger, Maurer said.
The blaze was not expected to be contained until at least dawn today, he said. Winds and high temperatures on the ground hampered firefighters initially.
More than 20 state Forest Fire Service brush trucks, along with more than 150 people, battled the blaze with the help of heavy equipment and water dumped from a helicopter, which was pulled out of the firefight before dusk but was expected to resume work this morning, Yuhas said.
"Our big concern right now is to keep everybody hydrated," Maurer said last night.
Yesterday's high temperatures on the ground - it reached 95 degrees in nearby Medford - created a sea breeze of about 10 to 15 m.p.h. off the cooler Atlantic Ocean.
The wind, combined with dry vegetation, led to the rapid spread of the fire, he explained.
"With the sun setting and the wind beginning to subside, they're making very good progress," Maurer said. "Most of it is just in the forest property."
The fire was classified as major once more than 100 acres were burned - a milestone passed before 6 p.m., said New Jersey Forester Jim Barresi.
The state Forest Fire Service had classified yesterday's fire danger as low.
Wharton State Forest encompasses parts of Burlington, Camden and Atlantic Counties. The fire was near Atsion Lake and the Atsion Ranger Station, off Route 206 near Shamong.
The cause of the fire was under investigation, Maurer said.
A headquarters was set up for the firefighters at the Atsion station.
The fire was in an area that burned in the 1980s, so there was not that much brush and vegetation to fuel it, Barresi said.
No homes or other structures were threatened, he said.
"It's just a matter of getting into it," Barresi said. "It's always a problem of access."
Wharton is the largest single tract in the state park system.
A wildfire this year in the Pine Barrens of Ocean and Burlington Counties burned 18,000 acres and forced 6,000 people to evacuate their homes.
That fire was sparked by a flare fired from a military jet on a training run at the nearby Warren Grove Gunnery Range.