The tree, named for the tunnel that had been carved into its broad base 137 years ago, was located in the Calaveras Big Trees State Park and toppled Sunday, the Los Angeles Times reports.
“We lost an old friend today,” wrote county resident Jim Allday, who posted a picture of the fallen titan on his Facebook page.
His photos show the tree trunk splintered heavily at its base.
Visitors could once drive through the tree, but it was most recently open only to hikers along a 1.5-mile loop.
The giant sequoias in the state park — the tallest of which is 250 feet — are estimated to be more than 1,000 years old.
“This iconic and still living tree — the tunnel tree — enchanted many visitors. The storm was just too much for it,” the Calaveras Big Trees Assn. said on its Facebook page.