Rocky Mountain National Park, Colorado, to Moab, Utah

Estes Park has a little of that Malibu, Carmel, Aspen sort of pretentiousness - lots of touristy stores and restaurants trying way too hard to be ultra-cool, rather seedy tourists ditto, and aggressively indifferent customer service everywhere except Rocky Mountain National Park, where the rangers and others are as nice and helpful as they can be. But what a beautiful place the National Park is! It's quite a spectacle, from its wide, flat glacier basin, littered with boulders and smaller flotsam and jetsam left behind by the retreating glacier eons ago, to its subapline slopes streaked with meandering rivers gleaming in the sunshine and dense with evergreens (some of them sadly, but beautifully, showing the brownish-red foliage that marks their impending death courtesy of the western pine beetle), to its giddy alpine heights, where it's too cold and windswept for any but the smallest plants and hardiest animals to survive. The plants are tiny and even closer to the ground than the high desert scrub we're used to; here, they're all but underground. It's 70 degrees or so and sunny at the Park's entrance, 50 and grayly threatening up at 12,000-plus feet.

Unfortunately, our exploration of the Park had to be cut short. At 10,600 feet, I suddenly developed the headache and dizziness of altitude sickness. This never happened to me on past high-altitude trips, so I presume it's another regrettable side effect of having lost half the normal complement of vestibular nerves. Luckily, the cure for altitude sickness is simply to get lower, which we did as quickly as possible. But I can't offer pictures of the higher altitudes because I was too dizzy to take any.

Colorado's landscape is unbelievably peaceful, what with its huge plains that seem to stretch forever, its gentle green and tan slopes rising to steeper, still forested, darker slopes, and then further up to the craggy, snowcapped peaks that scrape the blue cloud-dotted sky. Every so often, there's an exposed granite slope or a ridge of sandstone buttes or those crazy mounds that look like broken mountains loosely reassembled into conical piles, these ranging from boulder-y hunks of whitish limestone or gray-black granite, to smaller chunks of orange sandstone rubble to splintered sheets of flinty shale, some black, some brown, some red. The land here seems as big as the sky did in Montana, and the sky is pretty sizable, too.

I70 is another gorgeous interstate highway with breathtaking canyons, slopes, trees and vistas basically every mile of the way. There were a few tense moments as we crossed Vail Pass. It's a little higher than 10,660 feet and I was driving. Sure enough, as we topped the crest, my head felt rather as if it had suddenly detached from my body. Gripping the wheel and breathing deeply did the trick, though, and I got us safely back under what is apparently my altitude limit for the time being. We have only two complaints about this part of the trip. There are none of the scenic overlooks and pullouts we've come to expect in gorgeous locales. Admittedly, they'd have to post them about every two seconds in this part of the country, but still, it would have been nice to have places (other than the shoulders of high-speed roads) to stop off, ooh and ahh, and take pictures. And Colorado drivers are apparently somewhat immune to the extraordinary beauty everywhere; if you slow even a little below the speed limit on any road to gape at nature, someone with Colorado plates zooms up and tails you impatiently.

After Glenwood Canyon, which is spectacular in a less-forested, more-sheer rock sort of way, we run into the Colorado River. At first calm and narrow-ish, the river picks up width and speed and becomes host to a virtual traffic jam of rafters. We follow the river down the western slope into Grand Junction, CO, and then into Utah. Not too long after we cross the border, Utah starts showing off its high-desert splendor: rounded mounds of gray, porous rock so striped and leathery-looking that it might as well be elephant hide; light tan rock shaped by erosion and wind into folds as soft as suede; high slopes of granite and shale, topped with vertically rippled sandstone buttes that in another few tens of millions of years will be hoodoos, separated along the lines that are already visible. And in the background, seemingly hovering just under the sky or possibly painted onto a gauzy backdrop, cloud-topped bands of hazy gray peaks.

Just before Moab, the buttes stack up into serious ridges and slopes and turn the extravagant red of ferrite-rich rocks. The scenery becomes surreal - bright red, with layers of green the color of silver patina, tan, khaki, sable and black. We're in the country of slickrock, fantastical arches, river gorges, mesas, and enormous mountain ranges. And, of course, the piercing blue sky, clear air, and arid heat of the desert. We breathe easier, literally, and feel clean, pure and, for the first time in a little over three weeks, gloriously dry.