Anatomy of a fire

Travis Moyer of the Oregon Department of Forestry amid the charred trees of an untreated stand.

When the Cache Mountain Fire swept into Black Butte Ranch, firefighters were able to make a stand largely because of forest management practices that were implemented nearly a decade ago.

"We started on this side of the Ranch, so we had enough done that we can see it's a success," said Lorri Heath, Cascade Division Fire Management Officer for the U.S. Forest Service.

Heath was referring to the forest management practice of "fuels treatment."

She was addressing an on-site public forum conducted by the Central Oregon Intergovernmental Council (COIC) just west of Black Butte Ranch.

The process involves the thinning of trees to reduce forest density, removing or burning of the debris, mowing to reduce brush, and "underburning" to consume dead vegetation on the forest floor.

Left untreated, a forest wildfire can generate intense heat that consumes and kills everything in its path. When a fuels treatment program in an area is complete, fires can be better controlled and the destruction limited.

The site chosen for the COIC tour clearly illustrated what Heath was talking about.

Along George McAllister Road to the west of Black Butte Ranch is a parcel of private land that was not subject to any form of fuels reduction.

Tall skinny trees on the untreated private land stand so dense that it is hardly possible to walk among them. Today, they starkly stand like blackened skeletons with scarcely a needle to be seen.

An adjacent parcel of land on the fringes of Black Butte Ranch has been undergoing fuels treatment since 1995 and stands in clear contrast to the untreated parcel.

Due to the intense heat of the fire in the untreated area, some of the trees on the treated land were badly burned; but, still, many of the larger trees survived.

The fire damage on treated land was progressively less severe in places that were farther away from the intense fire of the untreated parcel. As the distance increased, the height of scorching on individual trees became less and less until only the forest floor showed signs of damage.

It was there that the fire could be stopped.

"Treated areas permitted access and even the building of hand lines," said Travis Moyer, Sisters Unit Forest Manager for the Oregon Department of Forestry.

"In the untreated areas, flame lengths were 100 to 150 feet and we couldn't even get near it," he said.

Moyer pointed out where the treated and untreated lands touched.

"The fire crowned out on that private land, and the heat pulse burned the adjacent treated lands more there than elsewhere."

A crowning fire is one in which entire trees, including the crowns (tops), are burned.

Black Butte Fire Chief Ed Sherrel also noted the effects of the untreated forest land.

"The houses that were lost were right there by this crowning fire," he said. "Other places we stopped it dead."

Brian Tandy, District Silviculturist for the Forest Service, described the ongoing fuels treatment plan for the Ranch area.

He also outlined the features of a demonstration project designed to evaluate the economic feasibility of commercial tree thinning operations.

The goal, Tandy said, is to find a way to make thinning and fuels reduction more cost effective, or even self-supporting. Such a process has the potential to benefit long-term forest health, wildfire safety and job security for forest products employees.