YOSEMITE NATIONAL PARK -- Even as more than 4,000 firefighters battle the ferocious Rim fire -- the nation's top wildland fire priority -- they have to tread carefully in Yosemite National Park.
Much of the park is designated as wilderness, where vehicles and roads are prohibited by federal law. For fire commanders, that means that they can't deploy bulldozers to plow fire lines, nor can they send crews in with fire trucks. In extreme cases, officials order smoke jumping crews to parachute into backcountry and drop supplies and tools.
It is possible to obtain an exemption from the law's provisions, but incident commanders must get written permission to do so.
Another consideration in the park are the Tuolumne and Merced Rivers, which have federal protections as Wild and Scenic Rivers. Hand crews would try to avoid clearing around the rivers and fire aviation managers are mindful to give the rivers wide berth when dropping retardant.
"Everyone is very careful about that and they have experience with it," said Tom Medema, Yosemite's chief of interpretation. "So far, we haven't cut lines into wilderness areas."
The blaze – now entering its 12th day – has burned 187,466 acres and is on pace to soon become the sixth-largest fire in state history. The fire is 23% contained.
While firefighters have used the Tuolumne River and granite formations on the fire's northern edges to set up defenses, crews have found little to work with on the blaze's eastern front south of the Hetch Hetchy reservoir.
"They're in scouting mode," Dick Fleishman of the U.S. Forest Service said of fire crews. "There's not a lot of real good areas to get out in there and do a lot of work."
The Stanislaus National Forest is taking the brunt of the blaze, with the Groveland Ranger District making up most of the southern flank. The region has been hit hard by fires in the past, the most significant in 1987, which claimed the life of a firefighter.