I SPEND A WEEK in Canyon de Chelly and find that I could easily spend another. It takes me several days to trace the extensive network of foot trails—Bat Trail, Baby Trail, Bear Trail, Barboncito Trail—many of them making use of the old Anasazi foot- and toeholds. Sometimes it's hard to believe I'm in the USA, circa 2006. The passing vignettes seem impossibly pastoral, like a scene from ancient Arcadia. A man splitting wood. A herd of churro sheep cropping grass. A ruined hogan. Cottonwood leaves hissing in the breeze. A decrepit plow half swallowed by the earth. Two old women working at their looms. Orchards of scabby peach trees, heavy with fruit.

It feels like another country, another time. And in a way, it is. Maybe this is what Carl Jung meant when he called Canyon de Chelly the "essence of antiquity"—not just the presence of old things, but the seamless cohabitation of the ancient with the modern. I feel a kind of pleasant chronological vertigo. I know where I am with clarity. But when, I'm not so sure.

All week I've been feasting my eyes on the dazzling confusion of the canyon's rock art: serpents, lightning bolts, fret patterns, whorls. Menageries of headless birds in flight, human figures with insectlike antennae, antelope with crab pincers instead of hooves, bird-headed men, frog men, turtle men. And palm prints everywhere, ancient choruses of hands, hailing from the walls.

At a place called Newspaper Rock, which Adam takes me to on the last day, the designs are so densely painted that there seems to be a kind of frenetic dialogue going on. It's the Sunday Times up there—comics, sports, editorials, even crossword puzzles. Adam used to romp around here with his friends as a boy. "It was a cool place to be a kid," Adam allows. "But I didn't know it then. It was just home."

I find the cumulative message of all these queer drawings strangely uplifting. If the Grand Canyon continuously reminds us of our squishable insignificance in the vast timeline of geology, then Canyon de Chelly does much the same thing from an anthropological perspective. It reminds us at every turn that humans have been at this game a long, long time. In the scheme of Homo not-so-sapiens, we American moderns are just a passing phenomenon: nothing special, soon to be forgotten, and destined to be replaced by other folks different, but not very different, from ourselves. We're specks in a continuous anthropological record.

Those figures up on the walls are us.