Giant Sequoias

Giant sequoias (Sequoiadendron giganteum) do not simply grow—they accumulate time. Rising along the western slopes of the Sierra Nevada, these trees are the most massive living beings on Earth, shaped by centuries of snow, fire, and stillness.

Giant sequoias share their ancestry with coast redwoods and dawn redwoods, descendants of a lineage that flourished across the Northern Hemisphere millions of years ago. As climates cooled and grew drier, these ancient forests retreated to California’s Sierra Nevada, growing on west-facing slopes where accumulated snowfall could sustain their water needs through summer. For thousands of years, these sequoia groves were shaped by frequent, low-intensity fire. Indigenous peoples intentionally used cultural burning to steward the landscape, reduce flammable vegetation, maintain open forests, and promote diverse native species.

Unlike the coast redwoods, giant sequoias were never extensively harvested for timber. While many groves were logged after Euro-American settlement, sequoia wood proved brittle and poorly suited for lumber, often shattering when felled. Ironically, their limited commercial value may have helped save many of the largest trees from the fate that befell much of California’s old-growth coast redwood forest.

When giant sequoias first came to the attention of the wider public in the mid-1800s, many people found their immense size difficult to believe. Exhibits of giant sequoia bark and sections of trunks were displayed in East Coast cities and Europe, where some dismissed them as elaborate hoaxes. Yet public fascination quickly grew, helping inspire one of the earliest conservation victories in the United States.

In 1864, during the Civil War, President Abraham Lincoln signed legislation protecting Mariposa Grove and Yosemite Valley. This act predated the creation of Yellowstone National Park and marked a pivotal moment in the conservation movement, establishing the idea that extraordinary natural places should be protected for future generations. Giant sequoias became enduring symbols of that vision, featured prominently on the National Park Service emblem.

With the later suppression of both natural fire and Indigenous cultural burning, forests grew denser as shade-tolerant firs filled the understory. Fuels accumulated, young sequoias struggled to establish, and the ecological balance began to unravel. In recent decades, this legacy—combined with drought and a warming climate—has contributed to larger, more severe wildfires that burn hotter and longer than giant sequoia forests evolved to withstand.

Today, giant sequoias face a new chapter. Protecting these ancient trees increasingly means restoring the natural and cultural processes that shaped them for thousands of years, including the beneficial role of frequent fire.