It’s one of the largest wildfires in the Canadian Rockies, even getting dubbed the ‘Holy Sh--’ fire, but it has led to some positive environmental changes in the mountain parks.

Exactly a decade ago, during a particularly hot and dry summer, a thunderstorm on July 31 brought lightning that started five fires in Kootenay National Park.

The fires quickly grew out of control, getting its unofficial title because everyone who saw the fire from a helicopter had the same reaction: “Holy Sh--.”

“I’d seen a fair bit of fire in my career, but that was a wild experience,” recalls Rick Kubian, resource conservation manager with Lake Louise, Yoho and Kootenay national parks. “There was one point where were across the valley looking back and it was just a giant orange smile.”

It ultimately burned 17,000 hectares.

The Kootenay fire was among dozens burning in British Columbia and Alberta — including large wildfires threatening communities in the Crowsnest Pass, Kamloops and Kelowna.

Across Western Canada, hundreds of homes were lost, thousands of people were evacuated and almost $1 billion was spent to fight the fires.

It led to the development of a national wildland fire strategy in 2005.

“Suddenly, this was in everybody’s interest to get this right,” says Brian Stocks, who spent 30 years researching fire behaviour and worked on the strategy as a scientist with the Canadian Forest Service.

The strategy, he says, has been implemented only on a piecemeal basis — despite the potential for more damaging wildfires as more people chose to live closer to forests, firefighting equipment ages and the climate changes.

It came to a head with the Slave Lake fire in 2011, when 7,000 people had to be evacuated and about a third of the town was destroyed.

“It’s location, location, location,” says Mike Flannigan, a professor with the department of renewable resources at the University of Alberta. “If the fires are burning in Kelowna and Slave Lake and Barrier near Kamloops, it’s a problem.

“But if it burns in the backcountry, it’s actually healthy and beneficial for the forest.”

The fire ended up being good for the ecosystem in Kootenay, but it took a gutsy move by firefighters in 2003 to stop it from advancing into critical areas that likely saved the towns of Lake Louise and Banff.

“The potential was that they could spread out of the Vermilion Valley and into the Bow Valley,” says Kubian. “We were really challenged on both of those fires and felt like we were scrambling to keep up with them.”

It was still about 50 kilometres from the Banff townsite, but the fire was moving at a rate of two km/h.

They took a risk and lit a backfire 15 kilometres ahead, setting up a containment line.

“Ultimately, it resulted in the fires not moving into the Bow Valley,” he says. “It’s a common strategy, but it really takes some resolve to execute.

“It worked really well.”

Since then, Kubian says Parks Canada has changed its fire management strategy in the mountain parks.

“That year was a watershed year,” he says. “We had really good success when we backed up and saw the landscape at the right scale.