Amanda and I were looking for a destination that defied the defeatist mantra "Now that you're parents, forget about adventure." But we didn't want to recklessly endanger our 11-week-old son, Quinn. We didn't want to endanger his future either, so we were intent on a low-carbon outing. Oh, and we also wanted to spend our week away in true wilderness. We live to get out into remote parts of the planet and didn't see why the simple act of reproduction should change that.

"What did people do before coddling?" I asked Amanda as we Googled "gentle stretch river American West." "I mean, what about all those hunter-gatherers? Didn't they have to travel down rivers?"

My sweetheart agreed, as agreeable sweethearts tend to do. Besides, she pointed out, "Quinn's restaurant travels with him." Soon we found a promising route: a six-day float on the Class Zero unrapids of Utah's Green River. That launched a weeklong research project. The first step was to find an infant life jacket—no easy task.

The second step was to remember to pack the things that new parents always forget on a trip of any duration (say, to the grocery store): diapers and wipes sufficient unto the day, sun hats, rain hats, and an appropriately named Moses basket. At the very last moment we threw in a golf umbrella.

The last and highest hurdle, however, was overcoming the universal Social Seal of Disapproval against taking a newborn on a multiday backcountry trip, no matter how flat the water. Even adventurous friends remained dubious about our plans to travel far from emergency rooms and washing machines. As for our families, we opted for a policy of "don't ask, don't tell." As things turned out, it was a wise decision.

Day One of our familial float wasn't half over when we concluded that the societal knuckle-rappers might have had a point. Serious rethinking, even panic, came in the form of this question: Can an infant handle 108-degree temperatures? The question was moot because we were on the Green River now, with no Google and no turning back. As we glided past 200-million-year-old sandstone cliffs, newspaper headlines popped into our heads: "Irresponsible Hippie Parents Haul Helpless Infant Into Wilderness in Triple-Digit Heat, Bring No Antibiotics." All we had to shelter little Quinn was a structure we'd rigged in the center of the boat: Amanda's river-dipped sarong draped over the providential golf umbrella.

Within two hours of putting in, Amanda was weeping with worry, and I was contemplating setting a rescue fire. We hadn't even kept it together until lunch. We realized that, as in any serious adventure travel, Rumsfeldian known unknowns and unknown unknowns would arise, and we would have to deal with them: rain, blowing dust, equipment malfunction, and being briefly lost, to name a few. Normally, that's part of the fun. Factor in responsibility for a fresh-out-of-the-box firstborn, though, and soon we were wondering why we didn't just stay in a hotel. But one thing about traveling on a river when your truck is parked 47 miles downstream: There's only one way to go.

It was Quinn who saved the trip. We took out for lunch and, almost hyperventilating with anxiety, apprehensively peeked under the umbrella to find our little elf laughing out loud, beside himself with appreciation that we had decided to paddle him around on this giant water bed. He didn't want it to end—not for a diaper change, not even for a snack at the always-open, five-star Cafe Mamacita. In retrospect, of course Quinn had a blast: While we paddled in temperatures more common on the planet Mercury, he luxuriated under a dripping umbrella in his Moses basket.

Plus, he didn't have to help cook dinner, de-rig the boat, or set up the latrine. And forget about pulling his weight when it came to washing diapers—our campsite looked like an Okie settlement. No, our son was being carted down the river like Egyptian royalty, and it suited him just fine.

We woke up much more relaxed on Day Two—even more so when we discovered we were still in cell phone range and could call the driver who'd shuttled our veggie-oil-powered truck. She promised to summon the troops if we didn't check in by the end of our takeout day, six days later. That precaution belatedly taken, we actually started to enjoy the trip through the canyon's magical cliffs, imbued with more gnomes and pirates and monsters than Pixar ever imagined. Not only was our new son not standing (well, lounging) in the way of us having an adventurous life; in fact, he was reminding us to have fun. That is, until early afternoon on Day Three when the thunderclouds moved in. Now, of course, the worry became "Can Quinn handle a radical drop in temperature?" Giggling laughter during the deluge answered that one.

Quinn was having the time of his new life. His personal little ecosystem had the added advantage of being a kaleidoscope—every drip of water, every brush of his parents' hands, and each of the several hummingbirds that alighted on the umbrella's top, we noticed, created trippy patterns when viewed from within the sodden sarong tent. It was a mobile mobile. We were envious and vied for turns to check on him in his luxury box.

Not long after the storm moved on, one of the few other boaters we saw that week passed by and hailed us.

"Heard you have a newborn with you. How's he holding up?"
"He's having an amazing time," Amanda called.
"What a trooper," the boater responded.
"No, you don't understand," I clarified. "He's having the best time of all of us."

Indeed, I can't say the final four days were the most relaxed in our river-running lives. On the one hand, we sang a lot, causing echoes in the cliffs and fear among the canyon wrens with our unfortunate choices of Billy Joel and Harry Chapin tunes. But every time I put one fear to rest, Amanda would come up with another: Could Quinn handle four or five mosquito bites? Was it dangerous the way the sun reflected off the river into his sensitive blue eyes? Was the river water we were filtering and drinking (essentially liquefied silt at this time of year) safe enough for Amanda to turn into milk?

Yes, no, and yes. Quinn loved sleeping in the tent, nursing in the boat was no problem, and he even got a couple of filtered-water baths. It was those unknowns that kept gnawing at us.

"We brought that umbrella as an afterthought," Amanda said with a shudder by the campfire on Day Four. "Imagine if we hadn't?" I put on my Confident Man hat as I flambeed a marshmallow. "But we did bring it," I said. "That's how life works." Still, a lot could have gone wrong on the river. Heat, cold, dehydration, drowning, bad water, mosquitoes. You know, the usual stuff faced by all humans until a couple of hundred years ago (and still faced by about half of us). At least there were no saber-toothed cats or cave bears to worry about.

The fact is, this trip was our first serious test as parents. Could we stay in love despite the extra work (e.g., trying to hang diapers in a thunderstorm) of being an Earth-exploring family? Yes again. We left the banks of the Green in what I call "river mind"—that blissed-out, timeless state in which you forget where the ignition key to your truck goes. A week with nothing on the agenda but lazy floating, awed conversation about geology, diaper changing, and making out recalibrates your priorities and clears your mental desktop.

As for Quinn, he proved that an infant isn't like some piece of china to be preserved in a case. He's just another member of the family. We also found out that we don't just love him. We like him too. Though Amanda and I agree that as soon as he can walk, he's taking his shift setting up the latrine.

The squadron of small planes swarming overhead as we de-rigged, we found out later, was sent by our diligent shuttle driver, whom we couldn't call until we got back into cell phone range. She played it real small-town once we did. "Just sent some friends out to make sure y'all were all right," she said. "They saw you camped on that beach and reported back to me." Which I took to mean "You idiots." But my sweetheart didn't seem to notice. As we climbed out of the river valley and made for dinner in Moab, Amanda offhandedly suggested that we plan for a 20-day trip next time.