It starts with a terrifying ride at sunrise in an old van around precipitous switchbacks on Mineral Bottom Road, which some claim is the most dangerous byway in America. By putting in here, we avoid the difficult Desolation Canyon to the north. The five of us are young and old and middle-aged. We are inexperienced paddlers.

Once at the beach, the world slows down. Sage and willow bloom out of a mud hole and ratty river people in T-shirts and rubber shoes stand around. Everyone seems to be smiling. A limb-heavy cottonwood rises from the bank. I stretch out on its giant roots for a moment because I’ve read you can feel a tree’s heartbeat if you get close enough.

The river flows in deep brown wrinkles and folds. We slip into canoes and kayaks, weaving past Turks Head, named by the one-armed Civil War veteran John Wesley Powell a hundred and fifty years ago. A blue heron kites overhead, stirring the air.

Night after night, a white-faced ibis squawks. Night after night, we make camp on some shore surrounded by the red rock cathedrals. My father, seventy-six with bright gray eyes, repeats the warning: "We must make sure we don't go past the DANGER sign and enter Cataract Canyon, fourteen miles of dangerous rapids." We nod. Our section of the river is slow. We'll be fine.

At Anderson Bottom we drag our boats ashore to search for petroglyphs. The Fremont people cuddled into this canyon 1000 years ago, spending quiet hours sculpting clay figures adorned with ear bobs, jewelry, and tent-like clothing. They carved these same shapes into rocks. On one perpendicular stone I spot rectangular and triangular bodies surrounded by squiggly snakes, horned animals, and winged creatures. Sagas of men and women and beasts I can almost understand.

In our canoes and kayaks, we pass buttes, gorges, miles of marmalade slickrock, greenish fissile shale, light-colored limestone, and then: Upheaval Dome. No one knows exactly how the dome formed. Scientists speculate that millions of years ago, a meteorite one-third of a mile in diameter struck down, creating the fragile crystal vault. Above us the rim tooths into a set of cumulous clouds. The murmur of my oars pushing and pulling the water is calming. At Jasper Canyon we wonder at a granary shouldered into a cliff. Built of clay-baked bricks, perfectly round with a little door hole. What family, what community lived here? On the desert floor, barrel cacti are blooming in Day-Glo yellows and reds.

Back on the water, the gorge widens. Bands of amber, khaki, tan, and eye-white. My guidebook says the oldest band, closest to the water, is Paradox, a rock formed from fragments of gypsum, anhydrite, salt, shale, sandstone, and limestone.

The current picks up, white water rushing toward us and falling away, and suddenly my seventy-six year old father yells, "We have to get to shore!" We're hurtling toward Cataract Canyon. We fly by the DANGER sign as we paddle furiously across the river, pulling hard but hardly moving. We reach the bank. It's choked with tamarisk. The water careen past as we grab the feeble branches. There's no way we can get on shore.

A few minutes rest and we let go of the branches, hoping for an opening. I hear shrieks and then everything goes silent. By some miracle, a blue heron flushes from the bank and we see what we couldn't before, a narrow channel through the tamarisk. My husband paddles up the drainage. The others follow as we oar up to a muddy end. We climb ashore and pant in the shade of an overhanging bluff for who knows how long, each reliving our near-death experiences.

Moving like robots, we make camp and build a small fire as we eat the last of our freeze-dried food.

A white-faced ibis squawks. Dusk already?

A few feet above us, the mosquitoes unscroll into the evening, females after blood to fertilize their vast unborn. Minutes later, bats appear: small, leathery, and blind. Finally, the swallows, who travel thousands of miles to live and die, dipping and swerving against the darkening fabric of the sky.