The wildfire scorched more than 88,000 acres after it was sparked by lightning in September.
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While the fire has not grown in recent weeks, it has continued to show activity in remote areas.
However, managers said significant rain events across the Sierra Nevada prompted the containment declaration.
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The fire forced the evacuation of many communities, closed public lands, and ultimately killed approximately 3% to 5% of the world's population of mature giant sequoias.