It was probably a French colonialist who first said the Vietnamese plant rice and the Cambodians watch it grow, but the Lao merely listen to it. In any case, Laos' 4.8 million people are just waking to the economic frenzy that has gripped most of their Asian neighbors. And the wild, mountainous northwest remains a land unto itself, where the main roads are the Mekong and its tributaries, and commerce consists of smuggling opium or consumer goods. So be prepared. Leave your credit cards at home, bring a mosquito net, and don't even think about room service.

I didn't have much time for my journey, which is a bad way to start any trip in sluggish Laos. I had hired an English-speaking guide through a Vientiane tour agency; we roared out of the Louang Prabang speedboat port, belching exhaust from the 35-h.p. automobile engine tacked to our stern. This was not environmentally correct travel. But it was a tremendous thrill. Through winding, verdant gorges, scents of musky earth and jasmine rushed at us, mixed occasionally with wood smoke from a riverside village. There were few other signs of life and almost no river traffic. For nearly three hours Somvang, our 32-year-old pilot, coolly serpentined through the rocks, dodging all manner of flotsam, including a dead cow.

As the late afternoon sun shaded the mountains around us, we hit a blinding squall that evoked the Mekong's tradition as "the Mother of All Waters." French diplomat Louis de Carne elegantly described much the same storm in 1868: "The colors of the sky all at once changed, the tints became deeper, the water turned a strange hue like withered leaves, the wind blew hard through the defile, the thunder echoed, and the hail (as large as musketballs) came down furiously." I donned my helmet and sighed in relief when Somvang finally pulled over for the storm to pass. At sundown we reached the honky-tonk port village of Pakbeng, which descends steeply to the river from a mountainside. Nothing like a blaring Canto-pop version of Country Roads and fish soup at the Bunmi restaurant to end a day on the Mekong.

In the morning it was west with the river to the Thai border and then north again. Four hours later our boat reached Houay Xai, a bustling, 5-km strip of a trading post 350 km north of Louang Prabang, and for us the end of the line. Upriver is the politically sensitive Burma border and, farther along, a series of rapids that make it difficult to continue all the way to China.

So I climbed into the back of a pickup truck for what proved to be a hot, nine-hour, bone-jarring detour east, through woolly Bokeo province, an opium-transit point and a major stage for America's "secret war" in 1961. By some local reports, skirmishes still occur intermittently between the Lao military and remnants of the U.S.-trained Hmong fighters (or their children). We did see what looked like a small patrol, with AK-47s slung over their shoulders. But the only real obstacles we faced in the dense jungle were washed-out bridges and a large tree, felled by the previous night's storm. Someday the same route is supposed to become part of a highway linking Bangkok and Beijing. It won't be as interesting then. Neither will Louang Namtha, the gritty frontier crossroads we pitched up in at midnight. Awash in Chinese entrepreneurs and their nouveau riche Lao counterparts, Namtha resembles a prospector's barracks with karaoke bars, cheap cognac and Chinese-speaking hostesses.

With more bad Canto-pop ringing in my ears, it was a relief finally to hit the road to Muang Xing. As we climbed to the top of a 2,032-m pass, the mountains that join the spurs of the Himalayas seemed to stretch forever. We descended into Muang Xing's morning market, where hundreds of villagers from the Golden Triangle's 39 hill tribes--Akha women with bejeweled headpieces and elegant, black-turbaned Yao--chattered next to stalls selling food, cheap consumer goods and Chinese medicinal herbs. When a popular television show ended at around 9:30 a.m., scores of villagers piled out of the lobby of a small guesthouse into a bevy of three-wheeled Chinese lorries. The market adjourned, Muang Xing's tidy main street seemed suddenly quiet, except for a drumbeat of hammering from inside a stylish, 100-year-old wooden building that the local government is restoring as a museum--despite an offer from a Vientiane hotelier. One can only hope ravaging commercialism doesn't reach Muang Xing too soon.