BISHOP, Calif. -- At 10,000 feet, the pine grove may be the highest natural history museum in the country, and with the serrated ridge of the Sierra Nevada standing 20 miles to the west, it may have the best vistas. Still, the high altitude and the stunning scenery notwithstanding, what will leave you breathless as you stand on the slopes of this arid, windswept stretch of California's White Mountains is the sprawling army of bristlecone pines around you, the oldest living trees on the planet.
Long before even the birth of Babylon, the stunted inhabitants of the Ancient Bristlecone Pine Forest were beginning their hardscrabble existence in this remote part of eastern California. The oldest of them, the so-called Methuselah Tree, is 4,734 years old.
Crouching against fierce winds, wringing precious moisture from the rocky limestone at their feet, many of the pines resemble huge versions of bonsai. Their elaborately sculpted limbs often are stripped of bark, and so tortured by the elements are the trees that they sometimes seem more dead than alive. Conversely, trunks of bristlecone pines that have been dead for centuries lie undecayed.
The forest overlooks Bishop, the largest town in this part of the Owens Valley, a parched conduit through which the Owens River drains the Sierras' snowmelt hundreds of miles southward to Los Angeles. Hikers and anglers flock to Bishop, particularly in summer, lured by the Sierras' 14,000-footers and opalescent lakes teeming with trout. Those who glance over their shoulders eastward to the majestic but bone-dry White Mountains and devote a day to visiting them, however, will find a fascinating tale of history and hardiness.
The Ancient Bristlecone Pine Forest, managed by the US Department of Agriculture Forest Service in the Inyo National Forest, is only 10 miles as the crow flies from Bishop, but the drive is circuitous. The access road to the forest is from the town of Big Pine, roughly 8 miles south of Bishop. From there, visitors drive 23 miles northeast over sometimes precipitous switchbacks, gaining 6,000 feet in altitude along the way.
In the forest's Schulman Grove, home of the oldest identified bristlecone pine, the visitors center is staffed by rangers and offers an introductory video program and exhibits on the trees and the methods used to date them. Two self-guided interpretative trails of varying lengths lead away from there.
Walking among the bristlecone pines (and their cousins, the limber pines, also long-living) one feels immediately the harshness of their environment. Winds strafe the slopes, the soil is powder-dry. Temperatures reach freezing six months of the year. No other vegetation exists, and it is this lack of competition from other plants that has helped the pines achieve their remarkable longevity.
Many of the trees are shrub-shaped, and few are taller than 40 feet. On most, only a thin sliver of bark runs along the trunk, showing finely etched grain patterns. So stressed are the trees that some of the living can be distinguished from the dead only by their verticality.
''People's reaction is one of awe and disbelief," said John Louth, a ranger who has managed the forest for 12 years. ''We get a lot of visitors who say they've waited all their life to see the trees. But when you stand in front of these trees, it's very hard to look at one and comprehend that it was alive when the pyramids were built."
A close examination usually reveals tiny bored holes in the trunks, remnants of the procedures scientists use to fix the age of these trees. The scientists -- dendrochronologists -- use a device called an increment borer to extract thin cross sections from trees. Cross sections provide a record of the tree's annual growth rings, bands that expand outward from the center of the tree, varying in width, and show a pattern of wet and dry years.
Surviving in such harsh conditions, bristlecone pines are extremely sensitive to variations in moisture and as a result are excellent recorders of climatic change. More important, cross sections from living trees have been overlapped and compared with those from dead trees to create a continuous tree-ring chronology that goes back nearly 10,000 years.
The process has proved to have valuable applications. For one, scientists study the ring patterns to gain an understanding of climate changes thousands of years ago, creating a field of study called dendroclimatology. Another use is in the dating of ancient artifacts. Scientists have compared ring patterns from timber used in ancient Native American structures with known patterns from trees in the area. Data gained from studying the bristlecone pines have been particularly useful in finely calibrating measurements obtained from carbon dating.
''The bristlecone pines made a significant contribution to our understanding of the reinterpretation of early prehistory," said Louth. For that reason, he said, some call the bristlecone pine ''the tree that rewrote history."
The Schulman Grove is named after Edmund Schulman, a researcher at the University of Arizona celebrated for his research into the tree-ring record. Schulman increment-bored and dated most of the trees in the grove in the early 1950s, and discovered the oldest living documented tree in the world, which he named Methuselah. (The Methuselah Tree is unlabeled, a ranger told me, to protect it from souvenir hunters and from people crowding under it to have their picture taken, thus compacting the soil around its roots.)
Another 12 miles north of the Schulman Grove -- and 1,200 feet higher -- is the Patriarch Grove, accessible on a dirt road. The Patriarch Grove takes its name from the presence there of the world's largest bristlecone pine, which has a girth of 39 feet, 5 inches and a height of 47 feet. It is, however, only 1,500 years old, and most of the pines in this grove are younger than those in the Schulman Grove. The Patriarch Grove also has two self-guided interpretative trails.
After wandering among these aged trees, so stark and intricately forged by their fight for survival, head back down the road. One more delight awaits before you descend to the Owens Valley and Bishop. Roughly two miles after you leave the Schulman Grove, look on the right for a turnout marked ''Sierra Viewpoint." An observation platform, with an illustrated sign identifying dozens of peaks, offers a brilliant vista of the Sierras, from Mount Perkins in the south to Mount Dana in the north. Another platform nearby looks southeast toward Death Valley. It's an exclamation point to an intriguing day.
Contact David Desjardins at email@example.com.