Dawn creeps gently over the rim of the canyon, a soft light bouncing from ledge to ledge, slowly illuminating the gorge below. The desert has cooled and the cicadas are finally quiet.

I wake to one of the sweetest smells in the wilderness: frying bacon. The park ranger have been up since 6 a.m. -- packing gear, getting ready for another day on their regular patrol down the river. This trip is by oar -- the service wants to set an example -- and soon we set off in our 16-foot rubber boats.

This landscape is both violent and serene. Mile-high walls, streaked red and black, stretch in a thousand patterns to the sky. Rock slides choke the river with boulders and the thunder of rapids echoes up the cliffs.

On a calm stretch, in early morning, the river glows silver. A beaver glides noiselessly across our wake. Overhead, four ravens chase a hawk.

At midday, life is in suspension. Scorpions and tarantulas have sought shade beneath the rocks.

Merle Stitt, the park's superintendent, trails a fishing line that is steadily ignored by the trout we can see through the clear water.

A dozen kayakers, bronzed and youthful, roll through the rapids in a rhythmic dance. Each boat emerges unscathed while we cheer from the shore.

In late afternoon, the river turns copper. We are down too deep to see the sun set, but we imagine it, as gaudy as a photograph from a picture magazine. At dusk, dark shadows drip from the canyon walls and the red rock bleeds into the water until we can no longer distinguish one from the other.

After supper, Stitt weaves tales of his days as a "buck ranger" in the Grand Tetons when Beavertooth, an old poacher, smuggled pelts out of the park in a coffin.

I drift to sleep, waking only briefly way past midnight to see moonlight edging down the canyon wall.

In a day, we have seen lava flows from ancient volcanoes, the limestone fossils from seas that receded millions of years ago, rockbeds nearly two billion years old and Anasazi Indian ruins eight centuries young. We have floated through geologic time.