SAN JOSE, Calif. — Investigators searching for answers into what caused the massive wildfire burning in and around Yosemite National Park have made some headway, fire officials said Friday.

Most authorities are mum about the details, but one fire official in Tuolumne County offered a tantalizing clue when he recently told a community meeting that the fire was likely caused by marijuana growers.

“We don’t know the exact cause,” said Todd McNeal, fire chief in Twain Harte, a town that has been in the path of the flames.

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.”

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“We know it’s human caused. There was no lightning in the area,” said McNeal.

His remarks, made Aug. 23, were recorded and posted on YouTube.

The Rim fire began Aug. 17 in a remote area of Stanislaus National Forest called Jawbone Ridge, far from any paved road. By Friday, the fire had burned 201,894 acres, making it the fifth-largest wildfire in California history. It was 32 percent contained; fire officials are estimating full containment on Sept. 20.

Over the past decade, the Forest Service and rural police have reported an increasing number of huge marijuana plantations being found in national forests across California and other states. The operations are run by Mexican drug cartels and are often guarded by armed lookouts, authorities say.

The growers have shot wildlife, rerouted streams and poisoned parks and forests with pesticides. They also have started fires.

In 2009, a huge fire that burned 90,000 acres in the Los Padres National Forest near Santa Barbara was set by a campfire from an illegal marijuana grow, Forest Service investigators concluded at the time. Law enforcement reported finding 30,000 marijuana plants and an AK-47 assault rifle in a remote canyon near where the wildfire started.

“We know that these illegal pot growers are out in our forests, and I think this fire just wiped out a whole bunch of them,” said Randy Hanvelt, chairman of the Tuolumne County Board of Supervisors.