Fire Allowed to Meander in Yosemite

As smoke again filled Yosemite Valley last week, a team of fire managers gathered in a cabin to discuss strategy.

Sipping a brown sludge resembling coffee, team members took turns talking about the weather and the previous day’s fire crew “casualties” of the cook’s latest stab at cooking.

By the time the meeting ended, a few ticks after 6:30 a.m., consensus had been reached on how best not to fight the wildfire creeping through the park’s southern wilderness.

Unlike the tens of thousands of fires that break out in Western forests each summer, this blaze is relatively unusual. Park managers not only welcomed it, but are doing everything within reason to let it burn until winter sweeps into the Yosemite high country and snuffs it out.

The fire has scorched about 7,500 acres in the 748,000-acre park. The 87 firefighters assigned to the blaze have spent much of their time shepherding the fire around, keeping it within a defined perimeter and making sure it doesn’t race out of control.

They also are showcasing the benefits of fire.

“What this fire is really about is ecosystem restoration,” said Tom Zimmerman, a commander assigned to the blaze, known as the Hoover fire, from his post in Boise, Idaho.

Although researchers have known for decades that wildfire has played a pivotal role in shaping Western forests, it wasn’t until 1995 that the nation’s fire policy formally endorsed the idea that fire can be good. In national parks, there is concern that not letting some parts burn lightly every few years can result in a buildup of dead wood that will cause a catastrophic fire. That could destroy forests and strip the land of its thin layer of soil.

For this reason, park officials were pleased when lightning ignited a fire in early July in the remote Illilouette Creek drainage area, in Yosemite’s back country south of Glacier Point Road. Like much of the park, the area is dominated by granite domes and ridges, with the valleys between filled with lodgepole, Jeffrey pine and red fir.

In late July, the park’s land managers made a crucial call: This fire would burn. Mountains would act as natural barriers that would keep the fire from spreading outside a “maximum manageable area.” There were no structures within miles. Few backpackers frequent the area.

The big concern was smoke. By late August, haze from the fire--and several others burning nearby--was filling the Yosemite Valley each night. The smoke often didn’t clear until midday, obscuring views of famous landmarks such as Half Dome, El Capitan and Bridalveil Falls during one of the park’s busiest months.

Chip Jenkins, the park’s acting superintendent, acknowledged that some visitors were displeased. But he also said that for too long, Yosemite and other national parks were managed primarily for visitors, while resource protection took a back seat.

“We want people to visit, that’s part of the reason we’re here,” he said. “The challenge is to get people to come and enjoy the park while at least holding up or improving the health of the land.”

Ecologists monitoring the fire said that although it may be counterintuitive, the benefits of the flames would be many. Trees that die will topple and disintegrate, nourishing the soil and insects.

Other dead trees--some killed by insects--will remain standing and be used by cavity-nesting birds. Pine cones will melt open and release their seeds, some of which will become the next generation of trees.

In the spring, melting snow will sweep nutrients released from dead trees into creeks, a boon to aquatic insects and the trout that prey upon them.

And, with room to grow, shrubs will quickly return and be filled with berries. “In two years, the area where the fire is will be some of the best black bear habitat in the park,” said Kate McCurdy, a wildlife biologist.

Last week, the park service took members of the media on a helicopter tour of the fire. Flying over Yosemite Valley’s south rim, an unusual and dramatic scene unfolded.

Unlike the fiery images of wildfires often seen on television and in the papers, this fire was smoky, with few open flames. Within the 6,500-acre area, there was a mosaic of alpine lakes, green meadows and patches of burned forest mixed with trees untouched by the fire. The high peaks of the Clark Range were a dramatic backdrop.

An open area filled with a few dozen tents belonging to the fire crew was the only evidence that this fire was not entirely being left alone. Sitting on one of the park’s domes, three firefighters ate lunch and watched fire and smoke crawl across the land below.

That morning, at the command post in Yosemite Valley, fire expert Dan O’Brien had predicted this is how the fire would, indeed, act.

“I think this fire is doing what it has been doing for thousands of years in the park,” O’Brien said. “Fire, insects, disease, that’s what shaped forests in the Sierra.”