This morning began with a helicopter drop in grizzly-bear terrain. Keefer led our group over spongy expanses of heath and heather and across vast fields of sandstone boulders, slowly snaking toward Buttercup Glacier. During one rest stop Bill Borgers, a Californian with a crooked smile and a carefree demeanor (he's an orange juice importer, which strikes me as a decidedly carefree way to make a living), gazed at a line of dots approaching the ridge about a half mile away. Two of those dots were his son and daughter, hiking under the wing of another CMH guide.

"Look at those little rats," Borgers said, chuckling. "They're laughin' at how long it takes us to get up there."

But within half an hour we geezers were standing on the glacier too. Algae growth has turned the snow pale pink in spots. When you scoop up a handful it smells like watermelon. "They say it takes about 200 years for snow to fall on a peak and end up at the foot of a glacier as ice," Keefer remarked, between puffs on his pipe.

Two hundred years amounts to temporal chump change here. This is a primordial landscape of lakes that were gouged out of the earth's crust ages ago by glacial action, of mountains thrust into being by the slow-motion collision of subterranean tectonic plates (geology's equivalent of a gang war), of delicate mosses and lichen that can take decades to grow an inch. Normally a wristwatch is of little use in a place where passing time is measured in eons as opposed to hours. But, alas, CMH has introduced speed to paradise. Keefer radioed for our helicopter pickup shortly after we had reached the top of Butternut Glacier. Now, as we float across the valley, I note how long we're actually in the air: 2 minutes, 50 seconds. It would take at least a day to cover the same distance on foot.

We disembark on the narrow runway of Pyrite Ridge. Different trail. Different geology. Similarly splendid panoramas. We pick our way over ground littered with acres of splintered shale. It's as if the gods had thrown a wild party and smashed the dinnerware between courses. The shale tinkles like wind chimes after every one of our footsteps.

"I've hiked many years in Colorado, " says Don Gore, an orthopedic surgeon from Wisconsin, "but have never seen anything like this."

Gore is a wiry, taciturn fellow with a trim mustache. He'd make a good New England country doctor. The day before I had hiked for a spell with him, his wife, Jackie, and their two grandchildren. The helicopter set us down upon a ridge overlooking a squeezebox succession of valleys. At one point Gore leaned on his walking stick, breathed in the surroundings, and offered up his opinion that heli-hiking makes a damn fine addition to one's recreational toolbox.

"I like to camp out," he declared, "but not if I can get there any other way. Look at that view!"