The annual growth rings of bristlecone pine provide a fascinating, 9,000-year record of the environment.

Very little vegetation thrives at elevations above 8,000 feet. But the bristlecone pine, Pinus aristata, lives thousands of years in the mountains of California, Nevada, Utah, Colorado, New Mexico, and Arizona.

Among these oldest of the world's living trees is a California specimen that actually is named "Methuselah," for the biblical patriarch said to have lived 969 years. This tree has lived more than 4,500 years, and still grows!

What secret does the bristlecone pine possess that enables it to thrive on the mountainous habitat it calls home? Gnarled by winds and stunted by the arid ground, these pines manage to survive by, of all things, learning to die slowly.

As bristlecones become old, they concentrate their vigor on a few branches, and thus prolong life. Even when completely dead, they resist decay and stand thousands of years more.

The wood of bristlecone pine yields firewood, fence posts, and mine shaft timbers for local use only. To archaeologists, though, its wood has provided a landmark revelation. By correlating the annual growth rings on both live and dead wood, scientists have been able to trace back weather patterns, volcanic reactions, fires, and other natural occurrences for 9,000 years.

Most importantly, traces of the radioactive isotope, Carbon I4, found in the dead wood of bristlecone pine at one location, exactly matched the carbon content of an ancient beam in the Mesa Verde cliff dwellings. This discovery allowed archaeologists to correctly date this civilization, and spawned a new research technique.

While the biblical Methuselah contributed only to legend, the bristlecone pine provides mankind with accurate records of the conditions in which it grows...then and now.