Peri Dare Van Brunt wept as U.S. District Judge Robert Coyle confirmed the sentence she had agreed to in a deal with prosecutors.
The guilty plea to three misdemeanor charges included restitution, which Coyle said he would deal with later.
The U.S. Forest Service saying fighting the 150,000-acre fire cost $148 million. The six-week blaze also destroyed three homes, a lodge and four commercial buildings, and endangered groves of sequoias, some of the world's largest trees.
Van Brunt, of Bakersfield, admitted lighting a camp fire without a permit on July 21, 2002, so she could cook hot dogs.
Van Brunt, who has a record of drug convictions, was jailed in April after violating terms of her release on bail by testing positive for drugs.
