Normally I wouldn't let a few downed trees get in the way of a good bushwhack. But as I surveyed the wall of redwood trunks lying across the creek that had been my pathway into the mountains, I had to consider the possibility that I had met my match. Each of these trees was at least 10 feet in diameter, and more than 250 feet long. Piled up like pick-up sticks hurled by a livid giant, the fallen trunks created a formidable barrier to further ascent.

My two companions and I sat down on mossy rocks to assess the situation. Going over the wall of wood was likely impossible without climbing gear, which is not allowed in the park. Going under might have worked, had we brought along snorkels and wetsuits. Going around would entail a battle with head-high nettles that ran up and down the 50 percent grade at creekside. From recent experience, we knew that the climb could take hours, and several pints of our blood.

We had come to this remote basin in northern California's Redwood National Park to hunt for the world's tallest living tree, a coast redwood nearly 380 feet in height. Explorers had discovered it last summer, in a remnant stand of old growth in the southern section of the park. Growing quietly on a mountainside for centuries, the newly crowned giant is some 70 feet taller than the Statue of Liberty, or about as tall as a 40-story building. Its discoverers christened it Hyperion, after the Titan (of Greek mythology) who fathered the sun.

The news was followed, as these things must be nowadays, by a press release. Emailed from the tourism people in Humboldt County, the message claimed that Hyperion "is too far from any trail to visit." But, it consoled, "adventurers piqued by the discovery have plenty of other opportunities to explore old-growth redwood groves in Humboldt County, the tallest, largest and most pristine in the world....