Tourism in Sequoia National Park. Car driving along a road between two huge Sequoia trees on the Generals Highway in Sequoia National Park, California, USA. Giant sequoia trees (Sequoiadendron giganteum) are found on the western slopes of California's Sierra Nevada Mountains at an altitude of between 1400 and 2400 metres. They reach 80 metres in height and 25 metres in circumference, making them the largest and most massive living thing on Earth. They are also the oldest, living for around 3200 years. Weighing up to 1.2 million kilograms, a sequoia is more likely to topple over before it succumbs to death from old age. Photographed in June.