Abraham Lincoln preserved majestic Yosemite sequoias. Now Washburn fire threatens them

The Washburn fire in Yosemite National Park was threatening some 500 giant sequoias, along with the community of Wawona.

Here’s a breakdown of what we know:

What is the Mariposa Grove?

It is steeped in the history of the American conservation movement.

“In 1864 President Lincoln signed legislation protecting the Mariposa Grove and Yosemite Valley for ‘public use, resort, and recreation.’ This landmark legislation holds an important place in our country’s history and was enacted at a time when the nation was embroiled in the Civil War. For the first time in our nation’s history, the federal government set aside scenic natural areas to be protected for the benefit of future generations. Later added to Yosemite National Park in 1906, the Mariposa Grove is a popular destination within the park,� Yosemite said on its website.

The blaze was the latest to menace the ancient giants, which are found in the wild only on the western slopes of the Sierra Nevada. Although they are adapted to thrive in fire, the sequoias are increasingly no match for high-severity wildfires driven by climate change, drought and decades of aggressive fire suppression that has resulted in a buildup of dense vegetation in some forested areas.

The grove was the subject of a $24-million restoration project that also improved access to its most popular sequoias, the Grizzly Giant and the California Tunnel Tree.

The grove closed in July 2015 to improve hydrology for the big trees and the visitor experience at the site, according to a park announcement Thursday. It reopened in 2018.

Some public parking, a gift shop and tram were removed because pavement was harming the roots of the trees and interfering with natural drainage.

Park officials said the grove has a history of prescribed burns to reduce brush and so-called ladder fuels, which they hope will help slow the fire’s spread. But they said that parts of the grove still have dense concentrations of dead plant material due to bark beetle kills that have plagued the Sierra Nevada. These infestations can become more destructive during droughts because trees are unable to produce enough sap to fight them off. And last year, a Mono wind event that tore through the grove felled at least 15 sequoias, which remain on the forest floor and could help fuel the fire.

What are fire officials doing?

Crews were spraying down trees in Mariposa Grove and scraping the ground to bare mineral soil to try to slow the fire’s spread, said Nancy Phillipe, a Yosemite fire information spokesperson. They were also wrapping some of the sequoias in protective foil, prioritizing the oldest named trees like the Grizzly Giant.

“This 2,000- to 3,000-year-old tree has a rich, vast history that goes back to Abraham Lincoln,� Phillipe said.

What is the status of the fire?

The fire had burned 1,591 acres as of Sunday morning. The fire started about 2 p.m. Thursday in the grove off the Washburn trail. The cause remains under investigation, but Phillipe noted the weather was clear and there were no obvious indications that the fire began naturally.

No containment had been reported as of Sunday morning. Officials were concerned that lower humidity and higher temperatures forecast for the weekend could help drive the fire’s spread.