Giant Sequoia National Monument, Nature reserve in Sierra Nevada Mountains, California, United States.

Giant Sequoia National Monument is a 328,315-acre protected area in the southern Sierra Nevada, administered by the U.S. Forest Service within Sequoia National Forest. It holds 38 of the 39 giant sequoia groves in that forest, about half of all groves still existing, including the Boole Tree, 269 feet tall with a 112-foot base circumference. The monument has two sections: a northern one around General Grant Grove and a southern one south of Sequoia National Park.

The monument was established by presidential decree in 2000 to protect thousands of giant sequoias and their habitats. This protection came after decades when the trees faced logging threats and habitat loss.

The Chicago Stump Trail displays remnants of a giant sequoia that was dismantled for a 1897 world's fair exhibition. This site reflects a time when these trees were treated as curiosities before protection became the priority.

The site remains open year-round, though winter weather can limit access to higher elevations. Visitors should wear sturdy footwear and bring plenty of water, especially for longer hikes.

The monument holds 38 of the 39 giant sequoia groves in Sequoia National Forest, about half of all groves still in existence. Among them stands the Boole Tree, 269 feet (82 m) tall with a base circumference of 112 feet (34 m), one of the ten largest giant sequoias.