The outdoors world has long been divided into two camps, mountain men and watermen, and rarely do the two mingle on a single trip. That's changing thanks to the packraft. Small, stowable, and surprisingly tough, a packraft is a rubber boat that fits into a corner of your backpack and transforms obstacles like lakes and rivers into highways.

To see for myself, I head to southern Utah's red rock country with Forrest McCarthy, a river guide with more than 20 years' packrafting experience. The plan: Backpack to the Green River, paddle through Labyrinth Canyon, then hike to a trailhead inside Canyonlands National Park – a three-day, 55-mile trip that would not be possible with backpacks alone.

We drive about 35 miles south of the town of Green River and park on a dirt road. We hoist our backpacks and begin walking past sagebrush and yucca, making our way down a creek bed, as blood red walls hundreds of feet high open and shut around us. After eight miles, we hit the wide, shallow Green River. "Just when you're tired of hiking, it's time to paddle," McCarthy says.

It takes five minutes to unroll and inflate our rafts. We grab our paddles – featherweight fiberglass oars that break down for easy storage – load our packs, and shove off. Suddenly, we're river men, paddling past impenetrable scrub and rock ramparts impassable for backpackers. It feels great to kick up my trail-weary legs and let my arms do the work.

We make camp that night on a wide sandbar and the next morning set off for a full day on the river, drifting in silence through cathedrals of red stone. After about three hours, we pull to shore and scramble up a steep trail to a saddle between two red buttes to take in the stunning views of Bowknot Bend, where the river makes a 7.5-mile loop before folding back on itself. A few hours later, we stop at a spot called Oak Bottom, build a driftwood fire, and watch the evening pull shadows up to the canyon's chin and tuck it into bed.

After a short morning paddle, we beach at Horseshoe Canyon. "Ready to hike?" McCarthy asks. I deflate the raft and shove it into my pack, and begin the 20-mile trek through lower Horseshoe Canyon.

As we ascend the dry bed of Barrier Creek, the red walls grow taller and even more dramatic. We set up camp on the highest ground we can find, to avoid the flash floods that constantly threaten, and awake at dawn to the call of a canyon wren. Soon we're hiking again. By lunchtime we are in the national park. A trail leads to the canyon rim and the Horseshoe Canyon trailhead, where we have left a second car.

As we drive, it occurs to me that on most trips, I'm plagued by "what ifs": What if we took that fork; what would we see if we could get 10 miles downstream? With a packraft, that's no longer a problem.

More Information: If you have packrafting experience, drive 34 miles south of Green River on County Road 1010 (Lower San Rafael Road). Take a left on Road 1025 (dirt, and unmarked), park, and walk into the sagebrush and yucca. In about two miles, angle toward Keg Spring Canyon on your right; find a ramp and descend. Walk and bushwhack to the river. If you're not experienced, head to Moab's Desert Highlights, which offers one-day outings. For trips in other areas, check out the website of the American Packrafting Association.