Alaska Sen. Lisa Murkowski appears to be winning a write-in campaign to keep her seat, according to unofficial election returns posted Wednesday morning. If victorious, she would be the first U.S. senator elected by write-in vote in more than half a century.

The final ballot counting could take weeks. Officials must verify how many of the write-in votes were cast for Murkowski, who opted to fight for her seat after losing to tea party favorite Joe Miller in the Republican primary.

But with 99 percent of precincts reporting, Miller had captured only 34 percent of the vote. Write-in ballots accounted for 41 percent of the vote, and Democrat Scott McAdams had received 24 percent.

"We are in the process of making history," a jubilant Murkowski told CNN early Wednesday. "They said it couldn't be done. ... We looked at that and said, 'If it can be done anywhere, it can be done in Alaska.' "

If she wins, Murkowski would be the first person elected to the Senate via write-in campaign since Strom Thurmond in South Carolina 1954.

Thurmond, however, had not lost his party's nomination in a primary. He launched his write-in effort when the incumbent died after winning the Democratic primary. The state party chose to appoint its own candidate - Edgar Brown - instead of holding another primary vote.

(In 1946, Republican William Knowland was elected to a two-month term in the Senate in a special election for which no names were printed on the ballot, meaning that all candidates were essentially write-ins.)

Murkowski told CNN that the write-in option "is a completely legitimate process. It's part of the election. ... I gave Alaskans that choice."

The senator, whose father was governor of Alaska and whose family has long been a part of the state's Republican establishment, said she planned to remain in the Senate's Republican caucus if she retains her seat.

"I am not my party's nominee, but I am a Republican," Murkowski said. "I caucused with the Republicans before. I intend to caucus with them again."