The General Sherman Tree at Sequoia National Park, California, is about 4,000 years old—making it the oldest living tree next to the bristlecone pine. It is 272 feet (83 meters) tall and has a diameter of 32 feet (9.75 meters) and a circumference of 101 feet (30.8 meters). The weight of the tree is estimated to be more than 6,000 tons. Approximately 150 million years ago, these giant trees were widespread across the Northern Hemisphere. While the size of these giant trees implies that they are composed of very strong wood, the opposite is true. The wood is useless as timber because it is brittle and shatters into splintery, irregular pieces when struck. Perhaps the weakness of the wood is why so many of these giant trees still survive and have not been harvested by the logging industry.