California's Sequoia National Park is most famous for its giant sequoia tree groves (Credit: Tuxyso, CC BY-SA/Wikimedia Commons)

The Sequoia National Park in California's southern Sierra Nevada mountains is best known for its namesake giant sequoias. The park boasts 40 groves of the massive trees, which occur naturally only on its western slopes. But the most beloved is the Giant Forest, a collection of 2000 trees that includes half of the Earth's largest and longest-living trees. This past weekend, the ancient wonders came dangerously close to being scorched by the KNP Complex Fire. But thanks to quick-thinking firefighters, the precious grove has been saved.

The fire personnel had taken the standard precautionary measures of clearing brush and setting controlled fires long before the blaze began heading toward the Giant Forest. But they knew more needed to be done to ensure the ancient wonders remained unscathed. On September 17, 2021, they took the unusual step of covering the base of some of the grove's oldest trees with protective aluminum "blankets." High on the list was General Sherman — the world's largest tree by volume. The grand tree, which is believed to be between 2,300 to 2,700 years old, stands almost 275 feet tall and boasts a 36-foot diameter.

Firefighters pose next to the foil-covered General Sherman (Credit: NPS.gov)

The specialized foil comprises aluminum on the outside, woven threads of polyester and fiberglass on the inside, and is laminated with a high-temperature adhesive. The park officials believed it would help deflect some of the heat from the flames and augment the natural insulation provided by the ancient trees' thick bark. They were right!

On Sunday, September 19, 2021, the officials reported that the extra precautions, which also included 24-hour timed sprinklers on General Sherman and the nearby park buildings, had worked. Jack Owen, a spokesman for the KNP Complex Fire Information Office, said, "There are no trees that have been burned yet, as far as in the grove or in the Giant Forest. Fire crews are pouring everything they can into it as long as it’s safe. We are just plugging along. That area is looking good.”

Unfortunately, the same cannot be said about the rest of the national park. The KNP Complex Fire — a combination of two fires ignited by lightning strikes on September 9, 2021 — has burned through 21,777 acres with zero percent containment. Meanwhile, the Windy Fire, which ignited further south on the Sierra slopes on the same night, has scorched over 21,598 acres with just 3 percent containment. Hopefully, the weather will cooperate and allow firefighters to gain control of the massive fires, which are now beginning to threaten nearby communities.

Resources: CNN.com, Fresnobee.com, Washingtonpost.com