Their mission was secret, and its location even more so.

As blazing wildfires scorched Australia, helicopters dived inside a gorge in the sandstone plateau. Deeper below, hundreds of feet past the looming cliffs, a team of specialists jumped out of the choppers to a site known only to a handful of people.

Their objective was simple: to save the trees.

In what Australian officials called “an unprecedented environmental protection mission,” firefighters were deployed in recent weeks into a remote sliver of rainforest, about 125 miles northwest of Sydney, to preserve wild Wollemi pines — a prehistoric species that was once believed to be extinct and is now considered one of Earth’s few living connections to the times of dinosaurs.

“With less than 200 left, we knew we needed to do everything we could to save them,” Matt Kean, environment minister for the province of New South Wales, said in a statement.

The scene of the government effort — which remained a secret until it was announced this week — was like a military operation. Water-bomber planes and air tankers encircled the area, located inside Wollemi National Park, spreading flame retardant. On the ground, firefighters tapped a river to moisten the soil and slow the approach of a potential fire.

Getting into the gorge, a mere crack between two cliffs, was a challenge, said Cris Brack, an associate professor at Australian National University. The operation posed a physical danger too. As they have raged across flammable eucalyptus forest, Australia’s wildfires have picked off bark and lit it aflame, meaning that in the worst of cases, fire could have fallen directly on top of the firefighters.

The risk was worth it, Kean said, to save a cluster of the pines alternately described as “dinosaur trees,” time-traveling clones and the Sydney Opera House of the natural world.

“We have this amazing plant that has effectively traveled through time and survived millions of years,” Matthew Brookhouse, a senior lecturer at ANU, told The Washington Post. “That would not just be a loss for Australia. That’s a loss for the entire world."

Contrary to its name, the Wollemi pine is not really a pine tree. It’s a conifer that resembles little else in the Southern Hemisphere, with spindly branches that shoot straight out of its trunk and bubbly brown bark that looks as if it’s been covered in Rice Krispies. At its highest, the trunk can reach 130 feet.

Most plant species have genes that vary from one plant to another, but the Wollemi pine is distinct, because each one is genetically identical to all the others, even those that stood in during the time of dinosaurs.

The stand in Wollemi National Park, Brookhouse said, is like a cluster of 200 identical siblings that have transcended time.

Steve McLoughlin, an Australian curator and professor at the Swedish Royal Museum of Natural History, told The Post that there used to be many more. The Wollemia nobilis was common across Australia from more than 100 million years ago to about 60 million years ago. But as the continent dried out while drifting north, about 30 million years ago, the trees started to disappear.

The trees were so sparse that for much of recent history, scientists long believed the “dinosaur tree” was extinct and lived only in the fossil record.

In 1994 they learned otherwise when a forest ranger was hiking through the Blue Mountains of New South Wales on his day off and noticed the unfamiliar plant, the only living kind in its genus.

Even after that discovery over two decades ago, there are just three tiny groves of the “dinosaur tree.” Scientists and government officials have kept the location of the stand a secret to avoid contamination.

How the trees got to that exact spot is a mystery. They’ve withstood extreme weather before, and some scientists say that they live only in their deep, moist ravine because that’s where they have been able to resist fires in the past.

But the fire this time is unusually hot and has spread farther than ever before, Brookhouse said. Within the bounds of Wollemi National Park, the Gospers Mountain fire has spread to about 1.24 million acres, about 10 percent of the total area scorched by bushfires in Australia this season.

The fires posed an existential threat to the Wollemi pines, saved in part by the firefighters and in part by the arrival of rain recently. But they could also lead to new discoveries about the rare rainforest environment and the unique soil in which the trees have thrived.