<P> The bristlecone pine has an intrinsically low rate of reproduction and regeneration, and it is thought that under present climatic and environmental conditions the rate of regeneration may be insufficient to sustain its population . The species are on the International Union for Conservation of Nature (IUCN) red list . The species are labeled under Least Concern (LC). The justification for this being that no subpopulations for Great Basin bristlecone pines are decreasing . Subpopulations seem to be increasing or remaining stable . Many bristlecone pine habitats have been protected, including the Inyo National Forest's Ancient Bristlecone Pine Forest in the White Mountains of California and the Great Basin National Park in Nevada, where cutting or gathering wood is prohibited . </P> <P> The green pine needles give the twisted branches a bottle - brush appearance . The needles of the tree surround the branch an extent of about one foot near the tip of the limb . The name bristlecone pine refers to the dark purple female cones that bear incurved prickles on their surface . The dark color of these cones help to absorb heat . After maturity, which takes about two years, the cones will become brown in color . These ancient trees have a gnarled and stunted appearance, especially those found at high altitudes, and have reddish - brown bark with deep fissures . As the tree ages, much of its vascular cambium layer may die . In very old specimens, often only a narrow strip of living tissue connects the roots to a handful of live branches . Even though the trees' needles may age, they still remain functional in regulating water and by their ability to photosynthesize . </P> <P> Bristlecone pines are known for attaining great ages . A specimen of Pinus longaeva located in the White Mountains of California is 7003506700000000000 ♠ 5,067 years old according to measurements by Tom Harlan . This is the oldest known individual tree in the world . The identity of the specimen is being kept secret by Harlan . Another well - known bristlecone from the White Mountains is Methuselah which is 7003484900000000000 ♠ 4,849 years old . Its specific location is also being kept secret . </P> <P> The other two species, Pinus balfouriana and Pinus aristata are also long - lived, though not to the extreme extent of P. longaeva; specimens of both have been measured or estimated to be up to 3,000 years old . It is believed that the longevity of the trees is related to the proportion of dead wood to live wood . This high ratio reduces respiration and water loss, thereby extending the life of the tree . </P>

Where is the oldest bristlecone pine tree located