NASA image: Rim Fire update Sept. 10, 2013

Hot and extremely dry conditions combined with shifting winds and low humidity continue to plague firefighter efforts at the Rim Fire in California. To date over 254,000 acres have been burned. Pockets of unburned vegetation around Thompson Peak and at the South edge of the fire's perimeter continue to burn. Fire crews successfully contained 15 spot fires along the Tioga Road today and the plan is to set a fire in a three quarter mile section of land within the park to contain an additional spot fire. Firefighters often have to set controlled burns in areas of dry tinder in order to keep another nearby fire from jumping to the dry tinder and growing expotentially. It is basically sacrificing a small area of land so that the lands beyond it can be saved.

The cost for battling the fire has reached $100 million. The fire remains at 80% contained. Even though containment remains constant, more vegetation inside the containment area burns and the fire intensifies within. The containment, though, has allowed scientists to enter the fire area to study the fire remains and determine what areas are most vulnerable to mud slides once the rainy season begins.

According to the Huffington Post: "About 5 square miles of the burned area is in the watershed of the municipal reservoir serving 2.8 million people - the only one in a national park. "That's 5 square miles of watershed with very steep slopes," Alex Janicki, the Stanislaus National Forest BAER response coordinator, said. "We are going to need some engineering to protect them."

So far the water remains clear despite falling ash, and the city water utility has a six month supply in reservoirs closer to the Bay Area."