A layer of cold, dense air kept the smoke close to the ground, allowing it to spread instead of dissipating closer to the park, said Lawrence Hajna, a spokesman for the N.J. Department of Environmental Protection.
"It's almost like it's hitting a pane of glass," Hajna said. "And that pane of glass is the denser air."
That layer is common during the change of seasons, he said. The distance smoke spreads depends on a variety of factors: the size of the fire, whether it's dry or wet, and the strength of the wind.
In this case, the fire's location - a remote part of the forest - complicated efforts by Forest Fire Service crews.
"It's very hard to get to," Hajna said. "There's sand roads out there, but they're pretty mucky right now."
Bulldozers were used to knock down trees in some areas to prevent the flames from jumping from one tree to another, Hajna said.
The spread of the smoky odor prompted the National Weather Service to issue an air-quality alert covering all of New Jersey from Burlington County north, as well as New York City and Westchester and Rockland Counties.
The weather service said fine particles could affect sensitive individuals, including the young, elderly, and people with respiratory diseases, such as asthma.
The rain Monday afternoon was expected to help clear the air.
Authorities of towns near the blaze, such as Washington Township and Hammonton, said they did not experience an increase in 911 calls because of the fire.
The nearest landmark to the blaze was Batsto Village, about three miles south of the fire.