Palin has a long history of run-ins with the Alaska GOP, forging maverick credentials that could complement Sen. John McCain's image.
With ethics the centerpiece of her campaign, Palin defeated incumbent Gov. Frank Murkowski, who served 22 years in the U.S. Senate before winning the governor's seat in 2002. In the general election, but she handily beat Tony Knowles, a Democrat who already served two terms as governor.
In an announcement, McCain's campaign said that Palin, who has been governor less than two years, "has the record of reform and bipartisanship that others can only speak of."
The campaign also said: "Her experience in shaking up the status quo is exactly what is needed in Washington today."
As governor, she successfully took on the oil industry, leading to a tax increase on oil company profits that has the state's treasury swelling.
Palin lives in Wasilla, a town of 6,500 about 30 miles north of Anchorage, with her husband, Todd, a North Slope oil worker and three-time champion of the Iron Dog, the world's longest snow machine race.
Her previous political experience consisted of terms as Wasilla's mayor and councilwoman and a stint as head of the Alaska Oil and Gas Conservation Commission.
While as chairwoman of the Alaska Oil and Gas Conservation Commission, Palin exposed current Alaska Republican Party Chairman Randy Ruedrich for ethical violations.
In 2005, Palin co-filed an ethics complaint against Murkowski's longtime aide and then-attorney general, Gregg Renkes, for having a financial interest in a company that stood to gain from an international trade deal he was helping craft.
She has also distanced herself from two senior Republican office-holders, Sen. Ted Stevens and Rep. Don Young. Both men are under federal corruption investigations.
More recently, Palin came under scrutiny by the Republican-controlled legislature, which is investigating whether Palin ordered the dismissal of Alaska's public safety commissioner because he would not fire her former brother-in-law as a state trooper.
The Palins have five children: Track, 19; Bristol 17; Willow 14; Piper, 7; and Trig, who was born in April with Down syndrome.
Palin was born Feb. 11, 1964, in Idaho, but her parents moved to Alaska shortly after her birth. She has a B.S. in communications-journalism from the University of Idaho.
