WASHINGTON -- Alaska Sen. Lisa Murkowski is -- financially speaking -- ready for 2016.

Murkowski spent 2015 amassing a multimillion dollar, record-breaking war chest for her burgeoning third-term campaign, thanks in no small part to her top-dog status in the high-dollar energy industry world of Washington, D.C.

In part, it's a lesson learned: the money she has now would have come in handy during her tumultuous 2010 election, when Murkowski scrambled to put together a write-in campaign to defeat Joe Miller, who took her spot on the Republican ticket after an upset win in the primary.

Just before the 2010 primary, she had just $1.8 million on hand, while her main opponent had only $84,200. Miller gained huge support from the Republican Party in the weeks that followed, while Murkowski gathered quick cash from Native groups and the energy industry.

Elections have only become more expensive since then. Given that candidates and their supporters spent nearly $20 million in Alaska's 2014 Senate race, it's a fair bet that Murkowski may need high stacks of cash this time around. So far there have been no "independent expenditures" in the Alaska Senate race, according to the Federal Election Commission.

This time around, Murkowski has collected nearly as much as she did during the entire two-year campaign cycle in 2015, before her campaign really got going. At the close of 2015, Murkowski had just over $3 million on hand, according to recently released data from the FEC.

It's common for incumbents to "seek to raise as much money as possible ... in hopes of discouraging opponents from challenging them," said Anthony Corrado, a senior fellow at the Brookings Institution and professor at Colby College in Maine.

The Murkowski 2016 campaign website just went live, as did her first campaign ad on the radio. Challenger Margaret Stock, an Anchorage immigration attorney running as an independent, only announced her candidacy in February.

But Murkowski, 58, told supporters in November that things would be different this time around.

For one thing, this time she is chairman of the powerful Senate Energy and Natural Resources Committee, and holds a key spot as chair of an Appropriations subcommittee. That means big-time spending money for her campaign.

"Typically a committee chairman is going to be able to raise more money," said Richard Skinner, a policy analyst specializing in campaign funds at the Sunlight Foundation, a nonpartisan, nonprofit organization that helps track money in politics.

"When you combine being chairman of (the) Energy and Natural Resources (Committee) and representing a very energy-dependent state, you would think a very high percentage of her contributions would come from the energy industry," Skinner said. And given Murkowski's position in the Senate, "I think probably a lot of lobbyists for the oil and gas industry would feel that they need to have her on their side," Skinner said.

In 2010, Murkowski was part of the GOP leadership team, and ranking member on the energy committee, but Democrats held the reigns in Congress, and she was clearly caught off guard in the primary.

When she lost her primary to Miller, Murkowski resigned from her leadership role as the No. 5 Republican in the Senate, but retained her committee spot -- a deal negotiated behind closed doors at the U.S. Capitol that showed some still had hopes for her long-shot write-in campaign. Nevertheless, she lost major financial support during her campaign, as the Republican Party sank its support into Miller's candidacy.

In the years since she pulled off her historic write-in campaign, Murkowski has walked a fine line with the Grand Old Party, taking to heart the tough task of representing the more moderate constituency -- including quite a few Democrats -- that got her re-elected.

In the last year, Murkowski gathered at least $1.2 million from the energy industry and political allies.

In the energy arena, Murkowski garnered donations of nearly $900,000: from energy-related Political Action Committees (PACs); personal donations from high-ranking individuals in the energy industry; and a short-term PAC she formed with the head of the House Energy and Commerce Committee, Michigan Republican Fred Upton.

She gathered more than $375,000 from political PACs related to her friends in Washington, D.C., such as members of the Republican Party and groups supporting Republican women candidates.

Overall, Murkowski took in nearly $1.3 million in contributions from PACs. Of those, 25 percent came from energy industry groups, and 22 percent came from funds shared by other politicians' PACs. The rest of her PAC donations came from a smattering of industries, including seafood, shipping and health-related industries -- though none of those categories neared the $100,000 mark.

And that's not including nearly half a million dollars, total, that was transferred from three committees: "Senators Classic," "Winning Women 2016," and the "Murkowski-Upton Victory Committee," a short-lived PAC she created with the House energy committee chair for a fundraiser. It has since been disbanded.

And there is another pocket of Murkowski money: Murkowski's "Denali Leadership PAC," a fundraising mechanism largely used to distribute money to other candidates. It can't be spent on her campaign. In the last year, Murkowski has distributed more than $100,000 to other Republican candidates. Meanwhile, she garnered more than $280,000 from other lawmakers' leadership PACs in 2015.

Increasingly, "the chairs of key committees are expected to assist in fundraising both for the party" and other candidates facing difficult elections, said Corrado. Leadership PACs can help feed those contributions and defray costs, such as travel for raising money.

The largest source of Murkowski's campaign funds in 2015 -- $1.7 million -- came from "itemized" donations -- cash that came from individuals in amounts greater than $200. Any time a person gives more than $200 to a campaign, their name, address, employer and occupation must be reported to the FEC.

Most of that is scattered across a large range of supporters, and it's not always simple to tell what drove someone to give to the campaign. But often it's easy to sort -- such as the $2,700 donated by Oklahoma oil and gas billionaire Harold Hamm. Of those easily identified as such, nearly a quarter of Murkowski's itemized donations came from those in the energy industry.

And that energy-related portion is likely much higher. There are other telling ways to break down those itemized donations, such as by state. Though an occupation might not be listed, it's a fair guess that a dozen or so donors from Texas that maxed out over the same couple of days as 10 Texas oil-industry executives may be related.

Alaska was only the third-highest state from which Murkowski drew "itemized" individual contributions in 2015. California was number one, sending $429,207 her way. Texas ranked second, with $236,550. And Alaskans donated $181,261. If Washington, D.C., and neighboring Maryland and Virginia are combined, the "DMV" comes in fourth with $143,050 in donations.

Murkowski's campaign manager Steve Wackowski said she's been receiving strong support from Alaskans throughout her second term: 1,300 individual contributions amounting to nearly $500,000 since 2011.

In 2015, 333 Alaskans contributed $181,261 to Murkowski's campaign, according to FEC data of itemized contributions. She drew $31,517 in "unitemized" donations in 2015 -- contributions in smaller amounts with no donor data reported to the FEC.

Murkowski's campaign spending is just getting started.

Most of the money she spent in 2015 -- just over $1 million, according to the FEC -- went to fundraising. She spent just short of half a million dollars on fundraising, media and financial compliance consultants. About $100,000 went to catering and food at fundraising events, and between $60,000 and $80,000 each on travel and polling, respectively.

In the deeply contentious 2014 Senate campaign, where Republican Dan Sullivan unseated Democrat Mark Begich, spending was hardly limited to the candidates themselves. Cash poured into the state on behalf of both sides, creating a campaign advertising blitz never before seen in the Last Frontier.

So far, the conventional wisdom from national campaign watchers has been that Murkowski is sitting on a safe seat: She has plum leadership positions guiding legislation and spending for energy and public lands -- key issues for Alaska. She is a Republican in a state that is considered solidly "red." And any candidate will struggle to counter her major early funding advantage.

Murkowski's main challenger, Stock, is running as an independent, which could be limiting, financially speaking, without support from the national Democratic Party. Stock has said she has commitments that she thinks will make her competitive.

But Murkowski may have another hill to climb, depending on how things shake out in the presidential race. New York real estate magnate Donald Trump is currently in the lead to take the nomination, and some of his positions, and certainly his temperament, run counter to Murkowski's moderate style.

Murkowski has thus far shied away from backing any GOP presidential candidate, or offering much in the way of an opinion on Trump.

But Trump is aligned with former Alaska Gov. Sarah Palin, someone Murkowski has had a strained relationship with in the past. Murkowski had strong words for Palin when she stepped down before the end of her term, and at one point questioned her qualifications to perform in national politics. Palin, meanwhile, vigorously backed Miller, the tea party candidate who nearly booted Murkowski out of office in 2010.

If Trump -- and Palin -- garner more support on the national stage, it's unclear how that will play out for Murkowski down ticket in Alaska, particularly with an opponent who plans to focus on the partisan problems in Washington, D.C.

Correction: A previous version of this story said Sen. Murkowski was stripped of her role in Senate GOP leadership in 2010. She voluntarily resigned from the position after losing the Republican primary.