On our big raft on the Colorado River we live in swimsuits, water shoes, and SPF 30 sun-block. We have lifejackets too, but those come off whenever we pull up to the little sand beaches to hike the side canyons and creeks. If we get wet, the canyon heat dries us within a half hour. It all works. We get wet often.

There are twelve of us on a five day trip through a hundred miles of the Grand Canyon with two professional guides. Our raft is thirty feet long with big pontoons on the sides and is ingeniously configured to have much storage in the back. In the front there is a large padded flat area where the hearty among us can choose to ride when we enter the bucking water of the bigger rapids.

It’s hot at the bottom of the canyon, consistently about a hundred degrees every day, but there’s a soothing breeze created by the movement of the raft. Better still, there is the chilly grey-brown water of the Colorado River. Most rapids are mild; a few are epic. We are splashed often enough to offset the heat of the canyon very nicely. The air warms us; the water cools us.

At first the approaching rapid is only heard, a steady “kkkkkkkk” that grows louder among the rock walls of the canyon. Excitement builds and we sort ourselves out. The meek people are already in the back; adventurers align themselves to be in the very front where we get a firm grip on the safety ropes that stretch taut across the big front pad. Ahead the smooth water can be seen to speed up and slide into an extended patch of choppy water, a turmoil of brown troughs and mounds of water churning in place.

The raft slides down the first trough and much water flies at us, battering the line of people who whoop and scream. Two more big ups and downs and then immediately ahead is an extra deep trough with a big permanent wave breaking on itself. Our raft slips quickly down into the trough but has no hope of climbing such a steep wave and the bow instead plows through the foaming crest sending a huge quantity of water slamming through us. The impact is so strong that I’m sure someone must have been swept away. In just a few seconds it’s over. The water drains away and there is fist pumping and much hooting. I look around and notice that all souls are all still onboard, our white knuckled grip a testimony to our drive for survival.

By the third day we are completely accustomed to life on the river. We know that evening will find us camping on a small sand beach with cots and fold-out chairs and that the guides will prepare a wonderful meal and Chris will break out beer chilled by the river and that it will all be delightful. We also know that it will never fully cool off at night (this might just have something to do with being in the middle of that huge mass of sun-warmed rock that is the Grand Canyon!) and that we’ll spend the night sleeping in minimal clothing atop our sleeping bags on our cots, which is okay because there are absolutely no mosquitoes in the Grand Canyon. Not a one.

The guides tell us the Colorado is browner than usual due to big thunderstorms last week that flushed silt out of the many side canyons. The river is always cold because it’s released from the bottom of the very tall Glen Canyon Dam many miles upstream. Happily, the water in the creeks of all the side canyons is instead deliciously mild in temperature. Havasu Creek is a favorite for its mineral blue color that is so beautiful among all the cottonwood trees. Elve’s Chasm has a quixotic little waterfall perfect for leaping into a lower pool.

There are many side canyons with active creeks that have pools and waterfalls of various size. A few of us are enjoying a dip in a long narrow pool between walls of steep smooth rock when our guides describe with some astonishment how just two weeks ago this pool area had been dry and filled to its brim with gravel and how they had hiked across it without giving it a second thought. We tread water, pondering such a thing, marveling at the transformative power of water here in this grandest of canyons.

There are long calm sections of the Colorado when everybody quiets down and takes in the immensity of the canyon. The rubber dry-bags that hold everyone’s gear are lashed to the sides of the padded front deck and make for comfortable seating. One is serving as my headrest as I let the sights come to me. Sunhat tilted just right, I drink in the unending panoramas of billion year old rock stacked high in tawny layers of golds and weathered browns. Entire side canyons drift in and out of view, unexplored worlds unto themselves.

I mull what a billion years feels like. If I consider my half century on the planet and take twenty units of that, I have a thousand years. Keep a hold of that and stack a thousand of those millennia together and we have a million years. I’ve already lost the ability to fully embrace such enormity . . . . and it would take a thousand of those units to reach a billion years. And the bottom of the canyon is cut into rock almost double that age. Yikes.

I try another way into that immensity: I pick out one of the horizontal strata of weathered rock halfway up the cliff and consider how it was once soft mud on the bottom of some ancient ocean when life in that briny sea consisted of little wiggly things with antennas. I hear there are fossils of single cell organisms in the older rock.

Up high by the rim, I see two birds lazily circling about like hawks patrolling a territory. They are pleasing to watch. The scale of this place still eludes me until I realize just how tall those cliffs really are and how those cannot be ordinary birds.

So this is what condors look like from a half mile below, I tell myself. How cool is that? For some reason I don’t mention this sight to my boat mates. Anyway, probably there will be more sightings to come that I can point out. (There weren’t.) Later I will write about it in a newspaper column, but for now it’s my private moment, a favorite from this five day adventure. I have seen the descendants of pterodactyls keeping a vigil over an ancient and sacred place.

Around another bend in the canyon walls comes a familiar sound – a dull roar that slowly grows louder. The languor of everybody is replaced by attentiveness. “Once more into the breach, fellas,” someone says. It’s time to sit up and seize the day. Nothing brings your attention back to the present moment quite like an approaching class 8 rapid.