California’s fire-ravaged sequoia groves have left scientists and forest managers scrambling to ensure a future for the world’s largest trees.

Over the past two years, nearly a fifth of all giant sequoias, once considered virtually immune to wildfire, burned so badly they died. Fire experts fear more lethal blazes are imminent.

This week, the effort to protect the cherished trees turns to Congress. In a rare show of bipartisanship, California’s Democratic Rep. Scott Peters of San Diego and Republican House Minority Leader Kevin McCarthy of Bakersfield plan to introduce the Save our Sequoias Act, a bill that would provide money and support to restore and help fireproof the venerable giants.

“It’s something we ought to be able to deal with,” Peters told The Chronicle, noting that even in the politically divisive Beltway, he’s been able to reach across the aisle for partners in the vital endeavor to safeguard the popular sequoia. “This is something as Americans and Californians that we all want to do right away.”

The famous trees grow naturally only in about 75 groves on the western slopes of the Sierra Nevada. Revered for their massive, 30-foot-wide trunks and towering heights of 250 feet, the titans can live for 3,000 years.

However, even with their thick, fleshy bark and need for heat to release seeds, which has allowed them to coexist with fire for millennia, California’s increasingly violent blazes have proved too explosive. Between Sequoia and Kings Canyon national parks east of Fresno and Giant Sequoia National Monument to the south, thousands of sequoias have fatally burned.

The Save our Sequoias Act builds upon a small but already emerging initiative to address the threat that extreme wildfire poses for the trees.

Under the legislation, which The Chronicle obtained an advance copy of, the existing Giant Sequoia Lands Coalition — a group of nonprofit, tribal, local, state and federal land managers who oversee many of the burned areas — could expedite forestry projects aimed at boosting fire resiliency in the standing groves, such as cutting fire lines, thinning brush and prescribed burning, as well as reforesting places where sequoias have died.

The bill calls for a federal emergency declaration, which would streamline regulations that can potentially hold up the work, including the Endangered Species Act, National Environmental Policy Act and National Historic Preservation Act.

The measure also would provide $325 million over 10 years for projects.

“We have to actively manage the groves to withstand the increasingly intense fires that we’re seeing now,” said Teresa Benson, supervisor of the Sequoia National Forest where many of the trees have burned, including Long Meadow Grove and its much-visited Trail of 100 Giants in the Giant Sequoia National Monument.

Benson, as a federal employee, can’t publicly endorse legislation, but she said she’s all for money to boost forest management.

“What we’ve long been relying on is the ability to use the workforce we have,” she said, noting that current staffing falls short of the challenge posed by the new era of dizzying wildfire.

The more destructive fires, scientists say, are driven by the buildup of vegetation that’s resulted from decades of fire suppression, on top of the drying and warming that’s come with climate change.

In 2020, the SQF Complex fires, an outgrowth of the lightning-sparked Castle Fire, killed an estimated 7,500 to 10,600 large sequoias. In 2021, the KNP Complex and Windy fires wiped out an estimated 2,261 to 3,637 big trees. Researchers started recording significant numbers of deaths from fire, albeit far fewer, in 2015.

About 60 of the groves that burned over the past two years are in McCarthy’s congressional district.

The House minority leader, who led a delegation of Congress members to Sequoia National Forest last month, has advocated for greater forest management not only to improve the health of the trees but to boost the safety of nearby residents and the vigor of the southern Sierra’s tourist economy.

“These natural wonders have stood tall for thousands of years, and their loss is a devastating blow to our communities and the environment,” McCarthy said in a statement to The Chronicle. “This bill would make commonsense reforms to forest management practices to reduce the risk of catastrophic fires.”

Republican Rep. Bruce Westerman of Arkansas, the only forester in Congress and ranking member of the House Committee on Natural Resources, also helped forward the legislation. Other sponsors include California Democratic Reps. Jim Costa and Jimmy Panetta and Republican David Valadao.

The authors say they hope the bill will be taken up as stand-alone legislation in the current session of Congress. However, with competing priorities in Washington, the item could get pushed to next year and bundled into a broader package, such as the farm bill.

While both Democrats and Republicans have expressed support, there are still sticking points for the parties. The streamlining of environmental regulation, specifically for clearing trees, has drawn criticism from the left before, while spending significant amounts of money can be unpopular on the right.

The Save the Redwoods League, a San Francisco-based conservation group and part of the Giant Sequoia Lands Coalition, has already begun prioritizing where future aid for the trees may be best directed.

The organization identified about 20 groves this month, and 2,000 acres of forest, that are most at risk of burning and “urgently” need help. The list, which is fluid, includes the prominent stands at Calaveras Big Trees State Park and Mariposa Grove in Yosemite National Park.

The groves were designated as vulnerable because they haven’t recently burned and therefore have more vegetation to fuel a catastrophic fire.

“It feels like cheating to say the priority is every single one,” said Joanna Nelson, director of science and conservation planning for the Save the Redwoods League, who helped create the list. “But over a course of about five years, we need to treat every grove.”

The alternative to more robust forest management, Nelson said, is to risk the very extinction of the cherished species.

“We could have these trees only in something that is zoo-like or arboretum-like,” she said. “Yes, I’m worried about them.”