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Rim Fire at 225,000 acres as Calif. officials search for cause of massive blaze

Mike Mcmillan / U.S. Forest Service via AP

In this Friday, Aug. 30, 2013 photo provided by the U.S. Forest Service, a member of the Bureau of Land Management Silver State Hotshot crew from Elko, Nevada, walks through a burn operation on the southern flank of the Rim Fire near Yosemite National Park in Calif.

The wildfire burning in and around Yosemite National Park has become the fourth-largest in modern California history, fire officials said Sunday as they tackled a blaze which is still only 45 percent contained after two weeks.

The Rim Fire has scorched almost 225,000 acres of California forests and over 100 structures have been destroyed by the fire, according to state fire officials. Eleven residences have burned down so far but a majority of the 5,506 structures currently threatened by the fire are homes, The California Department of Forestry and Fire Protection reported.

Firefighters continue to labor against the blaze known as the "Rim Fire." It is growing as much as 3,000 acres an hour and now covers 200,000 acres. NBC's Miguel Almaguer reports.

Firefighters managed to put out some small scattered fires overnight on Saturday, as higher humidity levels contributed to a slow in the rate of the fire’s spread. Still, while more than 5,000 active firefighting personnel are actively working to conquer the fire, officials do not expect full containment until Sept. 20, according to a fire incident report.

By Saturday afternoon, the Rim Fire became the fourth-largest wildfire ever in California, surpassing a 1932 fire in Ventura County.

The fire has burned nearly 350 square miles, essentially twice the size of San Jose or nearly 7.5 times the size of San Francisco, NBCBayArea.com reported.

Strong gusts of wind contributed to a sheet of thick smoke on Saturday that descended over Yosemite Park, which was crowded with holiday weekend campers. Even as air quality was rated as “very unhealthy” — the most intense level on a five-part scale — by the National Park Service on Saturday, the Associated Press reported that open campgrounds remained full.

On Sunday, the air quality in the park’s valley improved by one level to “unhealthy,” but campers were asked to avoid strenuous outdoor activity or try to stay indoors, according to the AP.

According to NBC Bay Area, two of the park’s campgrounds closed on Saturday and Berkeley Tuolumne Camp was entirely devastated by the blaze. Previous visitors to the scenic campground set up a memorial Facebook page that documented the site’s destruction.

As residents and campers lament the loss of favorite campgrounds and lush forest, California officials worked to determine the cause of the fire that has cost the state an estimated $60 million.

The cause of the fire is under investigation, but the possibility that it was started by an illegal marijuana growing operation was raised recently by a fire chief in Tuolomne County.

Todd McNeal, fire chief in the town of Twain Harte, west of Yosemite, said at an Aug. 23 community meeting that officials "know it's human caused, there’s no lightning in the area. … (We) highly suspect that it might be some sort of illicit grove, marijuana grow-type thing.”     

His comments surfaced in a YouTube video of the meeting.

The San Jose Mercury News reported that in June, 15,000 marijuana plants were pulled out the forest to the south and four miles of irrigation pipe were removed. The newspaper said a 40-acre wildfire the month earlier in the same area was blamed on marijuana growers tied to Mexican drug cartels.

Reuters reported that some officials said a failure to carry out U.S. Forest Service-approved tree-thinning projects, due to a lack of funds from Congress, has contributed to the swift spread of the fire.

John Buckley, the executive director of the Central Sierra Environmental Resource Center, told Reuters that the tree-thinning efforts "would have inarguably made the Rim Fire far easier to contain, far less expensive and possibly not even a major disaster."