AUGUSTA — Greeted with brochures reading “Sportsmen Are Under Attack!” and donation jars filled with small bills, outdoorspeople filed into the city on Saturday under the looming specter of a November referendum on Maine’s bear hunt.

Organizers said 30,000 people were expected by the end of the three-day State of Maine Sportsman’s Show at the Augusta Civic Center, attendance buoyed by the energy behind an impending vote on whether to ban bear baiting, hounding and trapping, sure to be a multimillion-dollar fight.

“People are just coming out of the woodwork for this,” said David Trahan, executive director of the Sportsman’s Alliance of Maine, which helps run the show and is leading opposition to the bear referendum.

The vote will be the second on the subject in 10 years here. In 2004, 53 percent of Maine voters rejected a similar measure, which would have made it illegal for hunters to use food, hunting dogs and traps to lure, pursue or kill bears.

State data from 2012 say that more than 3,000 of Maine’s 3,200 harvested bears, or 95 percent, were killed using those three methods. Baiting alone was used to kill more than 2,600 of them.

The referendum was brought this year by Mainers for Fair Bear Hunting, a group backed and almost entirely funded by The Humane Society of the United States, an animal-rights group. Trahan and others have formed a coalition called Save Maine’s Bear Hunt.

The Humane Society of the United States calls the practices barbaric and unfair, saying other states have managed bear populations well without those practices. In an email, Katie Hansberry, state director for that group, called the hunting practices “unsporting and scientifically indefensible.”

Twenty-seven states allow bear hunting, according to Born Free USA, another animal-rights group. However, baiting is allowed in only 10 states, Humane Society data show. Referendum proponents say Maine is the only state to allow all three of the methods they propose banning.

Gov. Paul LePage’s administration has said that 2,000 fewer bears would be hunted each season if the methods were banned, leading to possible overpopulation.

The hunt underpins a significant economic market in Maine: In 2004, a study paid for by pro-hunting forces said the state would lose $62 million annually without the hunting methods. It said 770 full- and part-time jobs would go away as well.

Their opponents criticized that study then. Recently, they have said more people come to Maine to see wildlife than to kill it, touting endorsements from animal-rights groups and veterinarians.

Hunting preservationists have a broader base of support, including many of Maine’s notable politicians, on their side. That group includes LePage and his opponents for governor this year, independent Eliot Cutler and U.S. Rep. Mike Michaud, D-2nd District, along with all five candidates hoping to replace Michaud in Congress.

U.S. Sen. Angus King, an independent ex-governor making the rounds at the show on Saturday, declined to take a position on it, saying, “It’s early yet and I want to think about it.”

The broad base of political support could be attributed to the fact that many guides in Maine’s poorer, most rural areas rely on the hunt. At the show, Matt Whitegiver, a registered Maine guide from Otis, in rural Hancock County, said 75 percent of his business is gained from guiding bear trips, and he’d be out of business without it.

In 2004, majorities of voters in only three counties — Cumberland, Knox and York — voted in favor of banning the hunting methods listed on the ballot. Hunters took just 17 bears in those counties in 2012.

James Cote, campaign manager for Save Maine’s Bear Hunt, said it was an example of a “two Maines,” north-versus-south phenomenon that he doesn’t think will happen again, saying Maine is “in this together.” For her part, Hansberry said “support for this campaign has been overwhelming.”

Cote said the campaign will have raised about $600,000 for the campaign by March’s end. By December’s end, Mainers for Fair Bear Hunting had nearly $760,000. Of that, $700,000 came from the Humane Society of the United States.

A brochure at the show for the pro-bear-hunting forces said they need to raise $2.5 million for the race to counter the other side’s “multimillion-dollar propaganda machine” that eventually wants to ban all hunting.

Hansberry didn’t say how much her campaign wants to raise, saying only it will have the resources it needs to win. She called the suggestion that her group wants to ban hunting a scare tactic because the other side “can’t win on the merits.”

It will be a loud race with far-ranging effect, right down to the dinner table of Steve Bickford and Lorri Nelson, of Standish, who said at the show that they haven’t eaten store-bought meat in four years, often subsisting on the bear and moose they hunt. The referendum could affect their lifestyle directly, they said.

“I don’t enjoy killing anything other than bugs that bite,” Bickford said, “but I put it on my plate and I know where it came from.”

Michael Shepherd — 370-7652mshepherd@centralmaine.comTwitter: @mikeshepherdme