Which U.S. state contains the natural groves of giant sequoia trees?

The U.S. state containing the natural groves of giant sequoia trees is California.

Giant sequoias grow naturally in scattered groves on the western slopes of California’s Sierra Nevada. Their native range is narrow, stretching roughly from the American River south toward the Kings River and the southern Tulare County groves. Many of these forests are protected in Sequoia and Kings Canyon National Parks and Giant Sequoia National Monument.

Giant sequoia is Sequoiadendron giganteum, a different species from the coast redwood, Sequoia sempervirens. Coast redwoods occur mainly along the foggy Pacific coast, while giant sequoias live farther inland in the Sierra Nevada’s mountainous environment.

The species’ natural distribution contains dozens of separated groves rather than one continuous forest. Some trees are among the largest living organisms by volume, and individual specimens can survive for more than 3,000 years. Giant sequoias also grow in planted locations outside their native range, but those introduced plantings are not the natural groves referred to in the question.