The Alaska governor's race is suddenly a three-candidate fight.

Former U.S. Sen. Mark Begich put the truth to long-standing rumors Friday when he filed to run for governor as the Democratic party nominee. Incumbent Gov. Bill Walker responded by announcing he will skip the Democratic primary – and avoid an August showdown with Begich – by collecting signatures to appear on the general election ballot as an independent. Both candidates will face the eventual Republican nominee.

That race to become the GOP gubernatorial candidate is heating up as well, with former Lt. Gov. Mead Treadwell filing to run less than an hour before the Friday afternoon deadline of 5 p.m.. He'll compete on the Republican side with Sen. Mike Dunleavy of Wasilla and Anchorage businessman Scott Hawkins.

Candidates said they expect the struggling Alaska economy, Permanent Fund dividend checks and crime to be among the hot-button topics. Here's what each of the contenders had to say about their motivations for running, and their chances, as campaign season heats up.

Begich back on the campaign trail

"I am running for Governor because the stakes could not be higher," Begich said in Friday afternoon email to supporters. "Alaska is my home and I will not sit back and watch our state continue to fall behind."

The former two-term Anchorage mayor, 56, appeared with his wife and teenage son at division of elections offices in Anchorage half an hour before the 5 p.m. filing deadline.

The decision followed months of discussion with his family, he said.

"I see huge opportunity but I don't see a vision, I don't see where we're headed in the next 20 years," he told a clutch of reporters.

Asked if he was concerned that his entry boost's the Republican nominee's chances, Begich said Alaskans will choose the candidate with the best plan for the state. He refused to share his views of other candidates.

"There will be a lot of people running, but at the end of the day, Alaskans will vote for who has the vision, who sees the future and who will tackle the tough problems out there and give them new bold ideas for that," he said.

Begich said he would discuss specific solutions and platforms further down the campaign trail. Debra Call, 63, of Anchorage, filed earlier in the day to run for lieutenant governor as Begich's running mate. Call, who is Dena'ina, is a member of the Knik Tribal Council and Cook Inlet Tribal Council board of directors.

The state's biggest budget deficits followed a sharp drop in oil prices starting in 2014 that gutted state income. To help cover the hole, Walker used his line-item veto power to cut the annual Permanent Fund Dividend in half in 2016, and agreed to cuts to the dividend by the Legislature the following two years.

Begich seized on those cuts in his letter to supporters: "With years of out-of-control state spending, when will we stand up to politicians that want a piece of your PFD instead of solving the actual problem?"

Parties react

The Republican Governors Association and Democratic Governors Association pounced on the news of Begich's candidacy.

"For months, Mark Begich and Bill Walker have been more concerned with playing a political game of musical chairs with each other than actually addressing the real problems facing Alaska," the association wrote in a statement attributed to RGA spokesman David Weinman.

"Now that this charade is finally over, voters can clearly see how both Begich and Walker support the same failed agenda of higher taxes, bigger government, and economic stagnation that got Alaska into its current mess," the statement said.

Elisabeth Pearson, head of the Democratic Governors Association, said Begich's candidacy gives Democrats a strong opportunity to win the governorship.

"Mark Begich has a record of bringing people together to get things done, and he will provide a clear vision to turn around Alaska's economy," Pearson said.

Walker: 'We climbed that mountain before'

Gov. Bill Walker, 67, said late Friday he's ready for the challenge of a three-way general election, with Lt. Gov. Byron Mallott, a Democrat, as his running mate on an independent ticket.

In a late-afternoon phone interview, Walker noted he was once a little-known candidate but in 2014 beat incumbent Republican Gov. Sean Parnell.

"Now I'm sitting here as an incumbent," he said. "We climbed that mountain before, and I'm comfortable with where we are."

He said he's relieved to know who he'll be up against, after months of speculation about who might challenge him.

"Fifty-two percent of Alaskans are independent and undeclared and that's the base we draw to," he said. "Our goal is to make sure we get Alaska fixed."

He said he inherited some of the problems Alaska faces, including a budget deficit that grew worse because of the plunge in oil prices that began in summer 2014, gutting state revenue. He said his administration has slashed the budget, cutting large numbers of state-funded employees and reducing programs.

"We've gotten a lot of (problems) taken care of already and I'd like to finish up the rest of them," he said.

Treadwell heats up Republican primary

"I hadn't planned to run," Treadwell, 62, told supporters in an email Friday.

"Alaskans have put a lot of work into this election already. But as we approached this day, many Alaskans all over the state were unsatisfied with our choices," he said. "After much prayer, and discussion with my family, I'm running to offer Alaskans a strong, pro-business, experienced conservative choice."

The word "conservative" was underlined. Treadwell said Friday by phone from Connecticut that he'll highlight his lengthy experience in business and government in a bid to win the Republican primary.

His record includes serving as lieutenant governor under Parnell starting in 2010, and as deputy commissioner for the Department of Environmental Conservation under Gov. Wally Hickel in the early 1990s.

Voters will want someone with experience for the big issues facing the state, he said.

"People will look at the whole slate of candidates and I think I've got a good shot," he said.

The Republican primary is Aug. 21. The general election follows Nov. 6.

Jim Lottsfeldt, a political consultant who has worked for Begich and Walker, said the numbers in the general will be in favor of the Republican candidate, given that Alaska is a red state.

Most people had viewed Dunleavy as the presumptive favorite in a three-way race, and Dunleavy appears to have the support of most Republicans, Lottsfeldt said on Friday, before Treadwell officially entered the race.

Dunleavy has been campaigning since last year, which Lottsfeldt said might give the Republican an advantage over Treadwell.

"I think the Treadwell campaign is too little too late," Lottsfeldt said.

But Lottsfeldt also said anything can happen in a three-way general election. Early Friday, Dunleavy campaign manager Brett Huber had shrugged off the prospect of facing Begich.

"We believed we'd win from the beginning or we wouldn't be running a campaign," he said.

"We'll continue to run our campaign and stay on our message," Huber said. "Mike believes he is on the right side of the issue and has a better direction to take Alaska than the track we're on."