Mike Law barged through punishing underbrush, angling for a closer look.

"Oh, my God, this thing is enormous. Look at that trunk," he said. "I don't know if it's the one, but it'll definitely make our list."

Law is on the hunt for an elusive quarry: the world's biggest tree.

He is one of a rare breed that has spent decades searching trackless corners of the Sierra Nevada, hunting a monolith that would surpass the giant of the giant sequoias, the General Sherman. The longtime title holder stands neatly fenced off in nearby Sequoia National Park, with a paved road to its doorstep delivering a steady stream of gawking tourists.

At 274.9 feet, the Sherman is not the tallest tree on the planet. That honor belongs to a leggy 367-foot coastal redwood near Ukiah, Calif., named the Mendocino. But the Sherman is the world's biggest in volume. Weighing 2.7 million pounds, it last measured 52,508 cubic feet -- that's counting all the wood -- and is still growing. It has reigned supreme since surveyors settled a fierce rivalry between Fresno and Tulare counties in the 1920s over exactly whose big tree was the biggest. Tulare won.

Ever since, rumors have abounded of a giant larger than the Sherman, like a landlocked Moby-Dick lurking in a sea of green.

Summer after summer, hunters doggedly tackle remote corners of the 70-odd groves of giant sequoias that dot the western slopes of the Sierra Nevada. They come with measuring tape, an old photo or topographical map -- and in recent years, surveyors' equipment and laser scopes. Their quest is unwavering -- and probably pointless.

"In the southern Sequoia, especially, you have to be a masochist to be out there and thoroughly explore them," said Nathan L. Stephenson, forester for Sequoia and Kings Canyon national parks. "There is a small possibility there could be a very big sequoia lurking out there -- less than a 1 percent chance. I don't ever want to say, 'There's no tree larger than the Sherman,' though. If I do, the next day someone will find it."

No one has hunted harder than Law and Wendell Flint. For 33 years, the two friends drove, hiked and thwacked their way through hundreds of miles of cragged Sierra forest in search of Sequoiadendron giganteum. As for Flint, "he's been doing it for 15 years prior to that," said Law, an apple-cheeked wall-design painter from Temple City, Calif.

Law often speaks as if Flint were still alive, scoping out a new specimen around the next bend. He died of diabetes complications two years ago, on a day he and Law were planning to take a trip into the national parks' Giant Forest grove once more. Flint was 82 and blind.

"He couldn't see the trees," Law said, "but he could smell 'em."

Flint and Law never did find the Big One, but they painstakingly measured 61 other giants, putting them on the list.

Law's quest this year in the Sequoia National Forest is as much about a lost companion as a phantom tree. He wants to discover one more giant and name it for his old friend. Flint would take his place on the list alongside Old Job, Chief Sequoyah and the others.

"I think if anyone deserves a tree, it's him," said Law, 63.

He has got a hot prospect, judging from aerial photos taken by an 87-year-old Sierra Club veteran named Martin Litton, and a decades-old photo of Litton's wife, Esther, standing at the base of a large tree. Litton knows where it is, he promises; he just never measured it.

The week after the Fourth of July, Law met up with Litton and a dozen others to head into the mountains to find it.

They made camp the night before at the same Redwood Meadow site where Law met Flint as a boy on a family camping trip.

They spent decades' worth of weekends and summer vacations tackling the backcountry, following tips from fishermen and loggers, and their own off-road hunches.

"It was a symbiotic relationship. They were meant to meet," said Flint's nephew, Robert Bergen. Flint spent hours hunched over graph paper, pencil in hand, devising formulas to accurately determine ground perimeter, diameters and total cubic footage.

Together they discovered Genesis, the Diamond, Three-Fingered Jack -- all mighty, but none the biggest.

Law is old-school. On this foray, a mattress wedged among sugar pines under the stars was his bed; a can of cold corn was be lunch on the trail. For dinner, he heated up a batch of "mountain mess": canned chili stirred into a can of stew.

The next day's prospect in the Tule River watershed looked to be a perfect candidate.

"I've got a feeling. With my 36 years of looking, I don't think I'll be wrong," he said. "From the aerial photos, it looks very promising."

According to Flint's own hand, the grove where they were headed had great potential.

"Offhand, I think the Tule River watershed is the best place to track down a new champion -- if one exists," Flint wrote before his death in "To Find the Biggest Tree," a bible among hunters of giant sequoias.

Law and his friends set off shortly after 8:30 a.m., shimmying in their all-wheel drives and pickup trucks up lumpy dirt roads to a metal gate blocking an old logging path. They descended on foot into patchwork hardwoods strewn with fading purple lupine and fire-red penstemon.

"This trail is what I call 'upindicular,' " said Law as they plodded through dusty soil and across rotting logs, keeping an eye peeled for timber rattlers.

The sequoias are mostly untouched. Their cross-grained wood shatters like a glass bottle when it hits the ground, and is not good for much more than grapevine stakes or roof shingles.

After several miles, several hours and a 1,000-foot drop in altitude, they encountered two graceful sequoias.

"Those are nice, but they're just average giants," Law said. Unless a specimen sprouted when Rome was the world's superpower, it does not begin to measure up.

"I'll tell you what Wendell and I do. If something looks really big -- say 20, 21 feet in diameter -- then we get a shadow measurement." Measuring the shadow's width "can be accurate to within an inch," he said.

The ragtag trail ended in an abrupt mess of "mountain misery": nonnative buckthorn brush that runs rampant on logged land.

The team struggled through, energy flagging. Litton slipped and tumbled into a morass of boulder and gooseberry. He looked like a mountain Methuselah with white whiskers and suspenders -- bleeding from both arms and an earlobe.

Law was up ahead, his spirits soaring.

"Now they are looking very, very good," he said.

He spied a really big one through the tangle. It rose from a steep slope, just as in the photos. It had the right look: a gnarled, wooly top, like a mutant broccoli spear, and a massive cinnamon trunk.

"Like a Grecian pillar," he exulted. "Goes straight up." He thrashed down toward it. "That may be his tree. I still can't see enough of it to make heads or tails of it," he said. "Once I see the ground, I'll know."

He emerged onto a scarred slope.

"This is it. This is our tree."

It is impossible to comprehend the size of a truly giant sequoia, 3,000 years old or so, until you are underneath -- head thrown back, gazing at a tree larger than the Statue of Liberty. The bark alone is 30 inches thick.

Each aging behemoth assumes its own shape, a grizzled totem sculpted by gales, lightning and wildfire. Law eyed the new specimen like a jeweler appraising a rough-cut diamond.

"That middle trunk certainly packs a volume," he said. "It's not a particularly tall tree. About 200 feet."

Bergen disappeared into the tree's enormous shadow, then hollered back, "No!"

Law slumped. He hobbled around the lower side.

"This isn't it," he said in a flat voice. "This is a very large tree, but it's certainly no competition to the Sherman." There is no point even naming it or putting it on the list, Law said, appraising it soberly. The hike back was hot and grueling. The crew gave octogenarian Litton a standing ovation when he made it, seven hours after they set out that morning.

Law hid it pretty well, but he was deeply disappointed.

That night, he reached inside his truck and pulled out a sheaf of well-thumbed 81/2-by-11 papers. It's the list, carefully typed by Flint. Precise measurements fill page after page:

"Sherman, Giant Forest; Rank 1, volume 52508 . . . year measured 81.

" Washington, Giant Forest; Rank 2, volume 47850 . . . year measured 76, 80.

"Grant, Grant Grove, Rank 3, volume 46608, year measured 76 . . . "

"I'm too old to do this," he said, nursing a knee the size of a grapefruit. "It's just not the same since Wendell's gone."

Mike Law sits at the base of what he thought would be one of the largest Sequoias ever found. The tree, however, did not measure up. Law has been searching for the giant trees for the past 33 years.