It is hard to say exactly when and where the holiday started, but most interviewed believe it sprang from high absentee rates among schoolchildren on the season's opening day.
Palisades was among at least three upper Bucks County school districts that canceled classes Monday but had teacher in-service sessions.
Superintendent Bridget O'Connell, a 14-year veteran of the district, said the tradition goes back as far as she can recall. And if that were to change, she said, it would likely represent a significant shake-up in the culture of the district.
"When I was teaching, kids would bring in deer jerky, and there's a real sense of pride in what they were able to hunt," O'Connell said. "They eat what they hunt - and it's a firm part of this community, for sure."
A similar tradition lives in districts in other states where deer hunting is popular, such as Michigan. In New Jersey, where the six-day deer season starts Dec. 9, officials said they do not collect school calendars, but have no indication that schools are closed.
No one tracks the data in Pennsylvania either, but many school districts in rural areas close on the first day of what is known as rifle deer season. (There are other limited deer seasons for hunters using bows and arrows and other types of arms.)
Even schools in cities such as Allentown and Harrisburg were closed.
Schools in the Southeast appear to be the exception, with Philadelphia and most of the 62 districts in its four suburban counties open.
Seven districts in the outlying parts of Bucks, Montgomery and Chester Counties were off Monday, though the reasons weren't always clear.
Montgomery County's Pottstown School District was closed, as were schools in Octorara and Oxford, both in Chester County's southwestern corner. Not every district could be reached Monday, and some officials were not sure why they had the day off.
Oxford superintendent David Woods said the schedule may have simply included an extended Thanksgiving holiday.
Woods responded to the inquiry by e-mail. He was on a hunting trip.
The first deer season in Pennsylvania was set in 1721, and allowed hunters to shoot deer between July 1 and Jan. 1. Those caught hunting in the offseason were fined 20 shillings, according to a history of the Game Commission.
Today, rifle deer season is far shorter - only two weeks - and carries much larger fines.
Efforts to meddle with the holiday have not been well received.
In 2006, the Bethlehem chapter of the NAACP met with resistance when it sought to allow school district employees to swap the first day of hunting season for Martin Luther King Jr.'s Birthday, which was not an official holiday at the time.
Today, King's birthday is a holiday in Bethlehem, but so, too, is the opening of hunting season.
Among legislative leaders, only House Speaker Sam Smith (R., Jefferson) was expected to be in the woods Monday.
Jay Pagni, a spokesman for Gov. Corbett, said the governor does not hunt, but "he supports hunting for wildlife conservation management and as a great American tradition."
Sen. Daylin Leach (D., Montgomery), an outspoken animal-rights activist and the Assembly's only known "out" vegetarian, said he would not be leading the effort to end the holiday in the Capitol any time soon.
"My plate is full, and with important legislation, not with deer meat," said Leach. "I don't consider the opportunity to slaughter God's creatures a priority."
Leach, whose district includes six school districts, said the General Assembly should perhaps consider taking off important religious holidays celebrated by non-Christians - such as Yom Kippur.
"It's a fasting holiday," he said. "So it's doubly good for the deer."
BY THE NUMBERS
12 days of rifle deer season, Dec. 2-14 (closed Dec. 8).
950,000 licenses issued this season by the Pennsylvania Game Commission.
750,000 hunters expected in the woods and fields on Monday.
343,110 deer were reported killed and tagged in Pennsylvania in the 2012-13 season.
1/2 of the antlered deer season's total harvest is taken on the first day.
$20.70 is the cost of an adult Pennsylvania resident hunting license.
250 total square inches of fluorescent orange material required on a hunter's head, chest or back.
3 hunting-related shootings were reported in each of the last three years.
Source: Pennylvania Game Commission
Inquirer staff writer Edward Colimore contributed to this article.