Burnout Totals 7,000 Acres – Meets Objectives

SEELEY LAKE – Despite concerns from near-by landowners, Greg Poncin's Type 1 Incident Management Team initiated a 7,000 acre burnout north of Cottonwood Lakes Road (Forest Road 477) Sunday, Sept. 10 on the Rice Ridge Fire. By Thursday, Sept. 14, ignition was complete and the objectives were met; bring the main fire 2.5 miles south to the shaded fuel break and Cottonwood Lakes Road while moderating the fire behavior to reduce the tree mortality and minimize spot fires.

The majority of the six-mile wide burnout took place on National Forest System lands. Approximately 40 acres of the Blackfoot-Clearwater Wildlife Management Area was impacted between Black Canyon and Dry Cottonwood Creek on the southwest corner of the burnout.

This area for the burnout is too steep and inaccessible for firefighters to slow or stop the main fire. By bringing the main fire to the Cottonwood Lakes Road, firefighters were able to fight the fire in an area that was more accessible with better access to supplies, water and medical support.

In addition to the Cottonwood Lakes Road, a 100-foot wide shaded fuel break was completed Monday, Sept. 11 north of the road towards the main fire area. Excess vegetation was removed from this area and hauled off-site. The shaded fuel break served as an additional buffer between the main fire and the road.

The majority of the burnout was lit from a helicopter. A firefighter certified in operating an Aerial Ignition System mounted inside a helicopter dropped Delayed Aerial Ignition Devices (commonly referred to in the fire world as "ping pong balls") onto the area to be burned at set intervals/spacing. Each ball contains several grams of potassium permanganate that, as it moves through the dispenser, is injected with ethylene glycol (anti-freeze), causing a thermal reaction.

By the time each ball reaches the ground, the thermal reaction has produced enough heat to melt the sphere and the flame produced ignites vegetation on the ground. The fire then spreads to surrounding vegetation.

A line of balls is dropped perpendicular to the slope starting at the top of the ridges. The small fires produced by each ball eventually grow together forming a long line of fire across the slope. As this line of fire grows, it becomes a backing fire, which moves down the slope at a low intensity.

A second line of balls is dropped downslope from the first line. If the second line of fire burns upslope, it quickly runs into the black line created by the previous line of fire above it before it can develop any intensity. By continuing stringing lines of fire down and parallel to the slope, the entire fire area will eventually back down close enough that crews along the Cottonwood Lake Road can do hand ignition to complete the burnout operation. If any of the burning lines start getting a little too intense, helicopters can drop water from buckets to slow the fire intensity.

By maintaining a low intensity fire, the tree mortality and spotting potential are reduced.

"Unless we bring the main fire to the fire line on our terms, the fire will eventually find a way to move down the mountain on its own terms which could have serious consequences, especially if the fire were wind driven and had a high potential to escape control lines," wrote Poncin's team in an Inciweb update.

Burnout operations started at 2 p.m. Sunday, Sept. 10 north of the Cottonwood Lakes Road and west of Monture Cabin. A helicopter lit the ridges running north to south from the main east – west ridge at the top of the mountain between Little Shanley Creek/Black Canyon Creek on the west and Cave Creek/Dunham Creek on the east. The fire backed downslope east and west off the ridge tops and into the canyon bottoms, slowly moving towards the fire line as a low intensity fire. Thermal belts at mid-slope elevations kept temperatures higher than in the valleys allowing active burning through the night.

Weather conditions continued to be favorable Monday and Tuesday, Sept. 11-12. Aerial ignition was done during the day and the Flathead Hotshots hand fired off the shaded fuel break along the Cottonwood Lakes Road from Cave Creek east to Little Shanley Creek finishing about 2 a.m. Wednesday morning.

A Red Flag Warning predicted gusty winds over the fire area which materialized Wednesday afternoon. Firefighters were still able to complete aerial and hand ignition on the south side of the fire to complete the burnout. Helicopters dropped retardant on the green (south) side of the Cottonwood Lakes Road to create a barrier to spot fires while the burnout was progressing towards the fire line.

The burnout was successfully completed when the Flathead Hotshots finished hand firing about 12:30 a.m. Thursday morning.

Incident Commander Greg Poncin looked at the burnout area and felt that the majority of the 7,000 acres burned were accomplished under low intensity according to the plan.

Poncin said, "There are a few areas where stand replacement fire occurred where fire intensity was higher than expected on the final day of burnout due to winds even though we went slower with our ignition that day, but they are relatively small compared to the total acreage of the burnout."