Bristlecone pine is an evergreen tree that grows at high altitudes in the Western United States. There are two species of bristlecone pines. One species, the Great Basin bristlecone pine, lives longer than any other kind of tree. These trees are found in California, Nevada, and Utah. Some Great Basin bristlecone pines are more than 4,000 years old. The oldest known living tree is a Great Basin bristlecone pine in the White Mountains of eastern California. This tree, named Methuselah, is more than 4,600 years old. The second species of bristlecone pine, the Rocky Mountain bristlecone pine, grows in Arizona, Colorado, and New Mexico. These trees live up to 2,000 years.