The Rim Fire began August 17 on the mountain ridges in Tuolumne County, Calif. (Photo via Inciweb)

The Rim Fire is out of control and has entered a remote section of Yosemite National Park.

In just six days, the blaze has grown to more than 105,000 acres — 65 square miles of nearly impossible terrain to conduct effective firefighting. The Rim Fire is spreading in two directions and just two percent contained with power lines and more than 4,500 structures threatened.

“It’s a monster,” the U.S. Forest Service’s Lee Bentley told The Associated Press. “It’s beating us up right at the moment. We’re fighting this fire very, very hard.”

In the next 24 hours the fire is expected to continue up the Tuolumne River canyon, and continue its spread to the north deeper into the Stanislaus National Forest and east into Yosemite, according to Inciweb. The only good news is the relative humidity in the area has risen from the mid teens 24 hours ago to between 39 and 50 percent.

A DC-10 next generation air tanker flies overhead on a run over the Rim Fire on August 21. (Photo by Steve Ryan)

While the fire has entered the edges of Yosemite National Park, the park itself has not been evacuated and the main roads in and out of the park to the south are still open and easily passable.

California Gov. Jerry Brown has declared a state of emergency, and thousands have been forced to evacuate the areas around the Stanislaus National Forest, where the fire began on August 17 along the rims of the mountains. The cause of the fire is still under investigation.

The 2,800 residents of Pine Mountain Lake are under an order to evacuate, while the 600 residents of the small town of Groveland have been advised to leave for their safety. The popular Strawberry Music Festival, which was scheduled take place at Camp Mather over the Labor Day Weekend, has been called off by organizers.

Smoke from the Rim Fire has created hazardous breathing conditions as far away as Reno, Nev., where outdoor activities and high school sporting events have been cancelled.

The fire grew in size by more than 50,000 acres just in the past 24 hours.

“The growth of this fire is just something you don’t see often,” Lynn Tolmachoff, spokeswoman for the California Department of Forestry and Fire Protection, told the San Francisco Chronicle. “If you get one a year, it’s unusual. If you get one every 10 years, that may be the norm.”

The Rim Fire grew by more than 50,000 acres in a 24-hour period, as crews struggled to effectively fight blazes amid the low humidity and steep canyon walls. (Photo via Inciweb)

Because of “inaccessible, steep terrain”, incident commanders for Cal Fire and the U.S. Forest Service say a combination of  direct and indirect attack will be used. Crews can’t effectively create line suppression along the canyon walls, which means air attacks on the flames are vitally important, with C-130 MAFFs and V-LAT DC-10s being used in suppression efforts. More than 2,000 firefighters are battling the blaze. Teams from the California National Guard’s 129th Rescue Wing have also been dispatched to help.

More than one dozen aircraft and crews from the California Air and Army National Guard — nine California Army National Guard helicopters and two California Air National Guard air tankers — are battling wildfires across Northern California, including the Rim Fire, American Fire, and Swedes Fire. Two UH-60 Black Hawk helicopters are assigned to the Rim Fire, according to the California National Guard.

Sources: ESRI, Inciweb, National Interagency Fire Center