We were just short of 15,000 feet when I decided that marrying Amy maybe wasn't the right choice after all. Red-cheeked and panting in the thin air, she was slogging up a grassy mountainside in eastern Tibet, fuming at me while coaxing along a small white horse that carried our baggage. Would this be my life—the shouting matches, the angry tears, the all-day silences along the trail? Her eyes blazed angrily as she trudged past. "Screw you!" she hissed. Except she didn't put it quite so politely.

My mother-in-law had warned us, "If your marriage can survive this trip, it can survive anything." The callow optimist, I dismissed this bit of wisdom as a mother's cluckings to protect her daughter from a son-in-law's half-baked schemes. "Naw, it can't be that bad," I replied. "I've made difficult trips before, and so has Amy." Which was true. But we'd never made them together or made them—I could barely utter the words, the concept was so new and strange—as husband and wife.

Married in April, we struck out for the Yangtze River in July. We'd start with a month-long trek along the headwaters and finish 3,000 miles downstream on a passenger boat docking in Shanghai. The point was to write a travel book about the Yangtze and to have an extended honeymoon in the process, though my true motives lay buried in a steamer trunk full of regret, ambition, and other psychic baggage that I unwittingly hauled along. At age 20, during a particularly troubled period of my youth, I'd attempted to reach the remote regions of the Tibetan Plateau and had turned back short of my goal. Now 33 and newly married, I would try again. This time nothing—least of all my wife—would prevent me from getting there.

I first sensed my dimming chances for success late in our first day on the trail while following a small tributary of the Upper Yangtze known to Tibetans as the Belly-Button River. That's when my bride, wielding an upraised spatula, chased our Chinese interpreter out of camp. Introduced to us simply as Little Cheng, he was the sidekick to Mr. Nian, our sullen and authoritarian government liaison officer. The two were contemptuous of both our Tibetan guides ("They never have a bath and they love to drink and fight") and of Amy ("You should do more to cook for your husband and wash his clothes"). That first evening, as she cooked the fish that one of the Tibetans had hooked, the two Chinese insisted on turning up the flame on the gasoline blowtorch they'd provided as a stove. "She ruined the fish!" Little Cheng crowed as dinner was predictably engulfed in a mushroom cloud of smoke. "She is not an expert!"

The second day started badly and turned worse. At breakfast, we ran out of water. As we loaded the yaks and horses, Mr. Nian and Little Cheng ordered the Tibetans about like slaves while tossing their noodle wrappers and empty lunch-meat cans in the meadow grass. We clawed our way up a high mountain ridge covered in fine, shifting talus and on the far side got caught in a thunderstorm. Later, while crossing a rain-swollen stream, Little Cheng slipped from his wooden saddle and tumbled into the rapids.

That evening, as we limped into camp in a yak-herder's corral, Little Cheng turned to me, trembling in anger. "Mr. Peter!" he barked. "Tomorrow Mr. Nian and I go home!" We'd already hit the balking point—when one or more of the party's key participants announce they'll proceed no farther—and we'd barely seen the Yangtze.

The next morning i was sitting on a boulder, lethar-gically dangling a fly rod over the muddy river, when Amy accosted me. She'd asked me to talk to Mr. Nian and Little Cheng about their poor behavior—toward the Tibetans, toward her, toward the trip for which we'd paid a very hefty sum. Now our fledgling marriage assumed the geopolitical tension between an oppressive China and a struggling Tibet. I told her I didn't want to confront the men because I was afraid that Mr. Nian would cancel the trip. "We have to stand up to them," she kept saying. "What they're doing isn't right." I ignored her, concentrating instead on casting my muddler minnow into the river, feeling like an embattled Ricky Ricardo in some high-altitude episode of I Love Lucy.

"You've got a problem between your employees and your wife!" she finally shouted in frustration.

I pretended not to hear. That's when she hurled a water bottle at me. It bounced off the boulder and plopped on the sandy shore, half in the water, as if it couldn't decide—like me—whether to float clear out of this canyon and out of this marriage or stay and stick it out.

I did stick it out, after an epic and hyperventilated argument with Amy up that grassy incline with the white horse in tow. It came down to my simple realization that this was as much her journey as mine, that we were in this together for the long haul. I then confronted Mr. Nian in a dusty stable after his surprise announcement that Amy and I weren't permitted by government order to enter Tibetan villages along this stretch of the Yangtze. "Goddamn it!" I screamed, hurling my notebook into a heap of dried yak dung as a group of nomads looked on in amazement. "This is China!" he shouted back, as if that explained everything. He demanded that I shut up, and when I didn't, he canceled the trek on the spot.

We were nearing its end anyway. Amy and I gladly left Mr. Nian and Little Cheng as soon as legally possible, dropped off the Tibetan Plateau, and made our own way along the Yangtze across China. Five months after we began the trip, we arrived, weary and battle-scarred, in Shanghai. We returned home and I sat down to write my travel book, but after many wobbly attempts I finally put it aside. It's only now, more than a decade and two children since our honeymoon trip, that I've completed the book. And it really has very little to do with the Yangtze River.

Peter Stark edited the anthology Ring of Ice, which comes out this month, and is now writing Last Breath: Death at the Extremes of Human Endurance.