Lightening Strikes Again

By JUSTIN DOMBROWSKI
All photos courtesy Rocky Mountain Type 2 IMT

Colorado's short-lived summer fire season came to a head on  July 7, when the Mason Gulch Fire erupted three miles south of Wetmore, Colo. Public-safety officials closed county roads and evacuated nearly 5,000 people. At the height of the incident, the fire threatened more than 900 homes. However, no homes were lost, and there were no serious injuries.

A helicopter fills up at a ranch’s fill site that firefighters
used to protect the property.

Attack Strategies

A lightning strike started the fast-moving fire that prompted immediate response from fire officials. A local Type 3 incident management team (IMT) initially managed the fire, but was later replaced by a Rocky Mountain Type 2 IMT.

On Aug. 10, the number of structures threatened jumped from 50 to more than 900, prompting officials to evacuate the community of Beulah. The following day, the Rocky Mountain Type 1 IMT took over command, with Incident Commander Jim Krugman in charge.

Fire officials set up the incident command post (ICP) at Florence High School, where they contracted to use the school's supplies, equipment, computers and phones. They even used a few classrooms so night crews could get some daytime sleep without enduring the sunlight and heat of camping outside. 

At the height of the incident, 831 personnel were assigned to the fire, including 20 handcrews (12 Type 1 and eight Type 2). Fifty-six engines, nine helicopters, two air-attack planes, three heavy airtankers and four SEATs worked the flames. During fire operations, air resources transported 6,207 lbs. of cargo and 110 passengers, and dropped 580,888 gallons of water and 325,809 gallons of retardant on the fire.

Structure Protection & Evacuations

Fire officials immediately prioritized structure protection and evacuations of threatened communities. Specifically, fire officials triaged threatened subdivisions based on their hazard level and placed firefighters and engines in strategic locations to protect the homes from the oncoming fire. Crews constructed fire breaks and conducted fire-mitigation measures around homes in the path of the flames. Such measures helped protect homes from the Mason Gulch Fire, as well as any future fire in the same area.

Many homes had existing defensible space, allowing for safer protection efforts by firefighters. Vic Voss, a resident of the Vaughn subdivision, a gated community in the evacuation zone, notes that he took wildfire-protection measures years ago. "I've got a 10' firebreak all around the house," he says. "The grass is down to stubs; the closest tree is 40 feet away; and I've got a composite roof."

IMT members coordinated an evacuation plan with the Pueblo and Custer County sheriffs and emergency managers. They also established trigger points for additional evacuations in case the fire continued to spread.

Additionally, the U.S. Forest Service and Colorado State Forest Service provided wildfire mitigation in and around the fire area. In one particular area, fire officials used a hydro-mower and other tools to reduce forest density. When the fire hit this area, its intensity decreased greatly, giving firefighters an opportunity to contain the fire at a small dirt road. This prevented the fire from making a major run across the road, where it would have threatened homes in the Wetmore subdivision.

Fire Behavior & Environmental Factors

Due to heavy winter snowfall, there was an unusually high level of dead material (up to 30 percent) in the oak and ponderosa pine fuels. Specifically, the heavy snow had caused branches to break, increasing dead vegetation on the forest floor. The heavy snow also caused many dead branches to hang from the trees, increasing the fire's ladder fuels. Such factors allowed surface fire to easily reach the canopy and contribute to crown fire events.

Oakbrush (Fuel Model 6), ponderosa pine (FM 9) and mixed conifer (FM 8) were the primary carriers of the fire; dead-fuel moisture levels in the 1,000-hour fuels were below six percent.

Further, a persistent high-pressure system maintained hot, dry weather with low relative humidity. Temperatures reached the 90s, relative humidity dropped into the low teens and diurnal, slope and valley winds dominated the air flow on the fire. Some thunderstorm activity contributed to strong, gusty winds and safety concerns for firefighters on the ground.

The fire burned primarily in a large, open valley, and on July 10, a localized northwest wind combined with hot and dry weather aligned with this valley. This caused the fire to take a major run in which it grew from 2,981 acres to 11,115 acres. This plume-dominated run produced rapid fire spread (1 mph), long-range spotting (1/4 mile) and more than 100' flame lengths. As a result, firefighters worked hard to rapidly construct fireline.

Additionally, Marc Mullinex, Rocky Mountain Type 2 incident commander, notes that on Monday night, what appeared to be a fiercely burning fire, which sent huge plumes of smoke roiling above the peaks, was actually the result of aggressive tactics by firefighters setting backburns to contain the flames.

The Mason Gulch Fire erupted three miles
south of Wetmore, Colo., prompting the
evacuation of 5,000 people.

High Tech Aids Low Tech

Firefighters used infrared (IR) imaging on the ground and during flights to determine fire spread and to identify fire perimeter and hot spots outside the line. Officials also used IR to plan crew assignments based on where the fire has spread.

In addition, firefighters used a more specific heat-sensing tool-a thermal (radiometric) imager. Pilots flew this helicopter-mounted tool along the fire's perimeter daily so it could sense heat at different levels. This helped fire officials identify areas where the heat was increasing and, therefore, where to direct crews. Additionally, the tool provides latitude/longitude coordinates, allowing for a more direct use of firefighting efforts during mop up and reducing the need for long-term gridding of the entire area.

The system costs about $9,000 per day; however, fire officials think it reduced costs on the fire by almost $650,000, considering they didn't need crews and equipment to search the entire fire perimeter-only the areas of concern. But more importantly, reducing firefighter time in the field during mop up reduces the chance for injury and improves the overall safety of the operation.

Firefighters also used other technology, including satellite and GIS, to identify threatened homes and roads so they could focus their efforts on structure protection and evacuations.

Dousing the Flames

Firefighters contained the Mason Gulch Fire on July 16 after utilizing 20 miles of handline, 1.2 miles of road and 0.2 miles of dozer line. The fire ultimately burned 11,357 acres (9,127 acres of Pike San Isabel National Forest land and 2,233 acres of private land), and it had a 21.4-mile perimeter.

On July 17, a weak cold front brought cooler temperatures and some precipitation to the area, which helped crews extinguish the remaining hot spots.

The Mason Gulch Fire was an example of the increasing issues in the wildland/urban interface, strong coordination among different fire management groups and the dichotomy of using both high- and low-tech methods to get the job done in a safe and efficient manner.

The Rocky Mountain News provided some information for this report.

Justin Dombrowski can be reached at dombrowskij@gmail.com.