In a major breakthrough in one of the largest wildfires in California history, federal authorities on Thursday indicted a hunter and charged him with starting the Rim Fire, which last year burned 257,000 acres in and around Yosemite National Park.

A federal grand jury indicted Keith Matthew Emerald, 32, on two felony and two misdemeanor counts.

Emerald, a former Half Moon Bay resident who now lives in Columbia, a Tuolumne County town near where the fire started, was deer hunting in the Stanislaus National Forest last Aug. 17, according to authorities. He allowed a campfire to spread out of control during a time that campfires were prohibited because of the dry conditions, court documents said.

The fire burned for nine weeks, charring an area nearly 10 times the size of the city of San Francisco. It cost taxpayers $127 million in firefighting costs. The blaze also threatened Hetch Hetchy Reservoir, a drinking water source for 2.6 million Bay Area residents.

“The impacts of the Rim Fire on our public lands will continue for years to come,” said Randy Moore, regional forester for the U.S. Forest Service.

Emerald told investigators he was bow hunting by himself in the remote Clavey River Canyon area of the Stanislaus National Forest when the fire started. He was rescued by firefighters in a helicopter as flames raced out of control. At first he denied causing the fire, blaming it on a rock slide and then illegal marijuana growers.

The Stanislaus, like many national forests in California, has had increasing problems with Mexican drug gangs growing large marijuana plantations in remote areas. There have been several arrests and prosecutions of growers in the Stanislaus forest in recent years.

Over months of investigation and interviews, however, authorities became convinced that Emerald was lying. He eventually signed an affidavit saying he had started a campfire to cook a can of soup and that winds blew its embers, starting the blaze.

He is charged with one felony and two misdemeanors in connection with starting the fire and one felony charge of giving false statements to federal agents.

Several days after the fire was blazing, a local fire chief raised the issue at a public meeting.

“We don’t know the exact cause,” said Todd McNeal, fire chief in Twain Harte. But he told a community meeting that it was “highly suspect that there might have been some sort of illicit grove, a marijuana grow type thing.”

Authorities from the U.S. Forest Service and Tuolumne County district attorney’s office who in September searched the area with Emerald near where the fire started in September, however, found no evidence of rock slides or illegal marijuana grows.

If convicted, Emerald faces up to five years in prison and a $250,000 fine.

A former resident of Montana, Emerald lived in various parts of California, including San Luis Obispo County, Pacifica, Half Moon Bay and Sonora, according to public records.

The fire, which ranks as the largest in recorded history in the Sierra Nevada and the third largest in California history, was named for the “Rim of the World,” a scenic overlook in the area.

More than 5,000 firefighters battled the blaze, which destroyed 11 homes, three commercial buildings and 98 outbuildings. The fire also destroyed the city of Berkeley’s Tuolumne Camp, which had been in operation since 1922. It also damaged a similar family camp operated by the city of San Jose.

The fire did significant damage to the local economy, particularly in gateway communities around Yosemite, such as Groveland, along Highway 120, which lost more than a month’s worth of business in a key part of the tourism season.

“It’s been really difficult. A number of businesses in Groveland are still suffering,” said Sherri Brennan, a Tuolumne County supervisor.

“Ranchers also have enormous challenges because of the fire. They lost miles of fences and corrals, and then they were hit with the drought. We also had some smaller private timberland owners who lost a lot of their investment and retirement when their trees burned.”

Since the fire, the U.S. Forest Service has proposed a limited salvage logging operation, which some environmental groups have opposed.

U.S. Rep. Tom McClintock, R-Granite Bay, has pushed legislation in Congress that would ease regulations to allow more widespread logging of the dead trees, but that bill has not passed. Meanwhile, fears of massive erosion into the Clavey River and other waterways have been reduced, largely because of the current drought, which has limited the amount of rainfall in the area since the fire.

Some tourism is coming back, Brennan said, but the area needs more.

“We really hope that folks in the Bay Area will come and visit up here and be part of getting Tuolumne County back on solid footing,” she said.

Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN