Where is the oldest living tree?

   In California's Bristlecone Pine Forest, within the White Mountains of the Inyo National Forest, stands a grove of ancient bristlecones. One gnarled tree here, named Methuselah, at 4,723 years of age, is considered the world's oldest living tree.
   The bristlecone pine tree (Pinus longaeva) is found in six western states (California, Nevada, Utah, Colorado, Arizona, and New Mexico), but the oldest known specimens—more than 4,000 years old—are located on the windswept, arid ridges of the eastern slope of the Sierra Nevada mountain range. They grow at an elevation between 10,000 and 11,000 feet, in alkaline soil. No other tree survives in this harsh environment. Bristlecone pines are 1,500 years older than the second oldest trees, the giant sequoias, but only about one-fourth the size, up to 60 feet in height and 36 feet in circumference.