The Bureau of Land Management says the Martin Fire, which stretches from Humboldt County into Elko County, has burned 435,869 acres, or 680 square miles, as of Wednesday night. That's a downgrade from 700 square miles declared Tuesday. Firefighters say it is the largest active fire in the United States. The fire is 65 percent contained. The Bureau of Land Management is offering a $2,000 reward for information leading to the arrest and conviction of the person or persons responsible for the fire. The Humboldt County Sheriff’s Office and the Bureau of Land Management Law Enforcement Division are requesting help from the public, saying the fire was human-caused.