Crews working to cut fire risk.

Byline: Scott Maben The Register-Guard

SISTERS - Last summer, the woods around Sisters and Camp Sherman were swarming with firefighters.

This spring, U.S. Forest Service crews are back to take a hard look at the damage from the 91,900-acre B and B Complex Fire, as well as reopen trails and remove more blackened trees that pose a public safety hazard.

But the focus isn't only on what burned last year in the Central Oregon recreation mecca. The agency plans to ramp up thinning, mowing and intentional burning in dense ponderosa pine stands outside populated areas in the Sisters Ranger District of the Deschutes National Forest.

State and federal fire crews burned more than 100 acres just south of Sisters this past week to reduce accumulations of woody material that could feed wildfires. The Sisters district hopes to use fire on 3,965 acres during the current federal fiscal year.

Officials eventually hope to thin and burn 8,000 to 10,000 acres a year on the district.

It's part of a multiyear effort aimed at creating a massive, crescent-shaped "fuel break" by clearing brush, dead timber and thick pockets of trees between the Cascades and developed areas on the eastern slope.

"It takes multiple years and multiple treatments to get some of these areas back to a condition where, if fires do occur, they will burn with low intensity and can be suppressed by crews without risk to their safety," said Kirk Metzger, an assistant fire management officer with the Sisters district.

The city of Sisters, Camp Sherman, the Black Butte Ranch destination resort and forested subdivisions such as Tollgate and Crossroads are marked as communities living under the threat of forest fire, Metzger said.

That threat erupted last year. Investigators said lightning sparked the Booth and Bear Butte fires that broke out Aug. 19, twice forced hundreds of Camp Sherman residents to evacuate and temporarily closed Highway 20 over Santiam Pass. Renamed the B and B Complex, the fires were contained a month later, after growing into the largest blaze in the state last year.

Forest officials have kept the fire area closed since last fall to keep people away from unstable snags, hidden holes where stumps burned away and other dangers.

"It's a real high-use area," said Kris Martinson, a spokeswoman for the Sisters district. "We have way too many acres of potential high-risk situations, both on and off roads."

The closure also is meant to limit erosion of soil exposed and loosened by the flames. "We do not want erosion to start before new growth has set down," Martinson said.

But with the arrival of spring, people are itching to return to their favorite recreation spots.

The Forest Service will lift its closure starting Saturday, when it will reopen some of the more popular roads within the fire's boundaries.

Other roads will reopen as snow recedes and officials evaluate roadside hazards, Martinson said.

"We have 291 miles of roads in the fire area," she said.

"We will not have a chance to make a thorough assessment and clean up the hazards on a lot of these until this summer."

A restriction on off-road use of motorized vehicles in burned areas will remain in place indefinitely.

Also this spring, forest officials are finishing short-range restoration projects. The work included improving road drainage systems to handle increased runoff anticipated where the fire stripped vegetation from the landscape.

The Forest Service will continue road improvements this spring by installing seven large culverts, again to handle greater volumes of water flowing downhill.

Crews already have felled thousands of trees that died in the fire and were leaning over roadways, and they'll resume the work this spring.

Other workers will monitor burned areas where noxious weeds are beginning to appear. It is easy for non-native vegetation to gain a foothold in disturbed landscapes.

Also slated for restoration work are miles of trails inside the burn, including areas in the neighboring Willamette National Forest and within wilderness areas.