(S)he sued Kempthorne, arguing that the Bush administration didn't use the best science in concluding that without further protection, the polar bear faces eventual extinction because of disappearing sea ice as the result of global warming.
Palin, McCain's vice-presidential running mate, has had frequent run-ins with environmentalists.
In her 20 months as governor, Palin has questioned the conclusions of federal marine scientists who say the Cook Inlet beluga whale needs protection under the federal Endangered Species Act.
She has also defended Alaska's right to shoot wolves from the air to boost caribou and moose herds for hunters, and - contrary to a view held by McCain - is not convinced that global warming is the result of human activity.
Environmentalists have nicknamed Palin the "killa from Wasilla," a reference to the small town where she formerly was mayor.
"Her philosophy from our perspective is cut, kill, dig and drill," said John Toppenberg, director of the Alaska Wildlife Alliance.
Palin is "in the Stone Age of wildlife management and is very opposed to utilizing accepted science," according to Toppenberg.
While acknowledging the climate is changing, Palin expresses doubt as to whether emissions from human activities are causing it. McCain, on the other hand, supports legislation to reduce heat-trapping pollutants, primarily from the burning of oil and coal.
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