For 750 miles, Highway 200 in Mexico tracks a coast that mixes great surfing, funky bars, cowboys, mountain towns, and beachside havens of great luxury. Ondine Cohane takes the trip

Surf etiquette dictates that I shouldn't reveal my exact location, but I am not far from Troncones, a small dusty village on the Pacific coast of Mexico, about half an hour north of Zihuatanejo. You can't get to this break by road, and you would have to search a lot of deserted beaches, board in arms, to find it—unless, that is, you can get Michael Linn, an Oregon native and now resident surfing instructor, to take you there. That is how I have the good fortune to be here on a warm afternoon in January.

The light turns golden as we paddle out in total isolation to the perfect sets that break first left, then right. The early hours of the day usually provide the best conditions for surfing, but today is an exception, the waves worthy of the pursuit. A sea turtle swims alongside for company. I tire before Michael and retreat to the edge of the lagoon as pelicans dive for their evening meal. Three kids fish with hand nets, up to their knees in the clear water. Behind them, the mountains are purple and hazy. An unusual quiet descends on the Pacific at this hour.

If this were merely a surfer's rhapsody, the afternoon would be idyll enough. But it's only one in a series of moments that occur on similar beaches in the course of a 750-mile road trip. Seven years ago, I learned to surf far to the north of here, in a town called Sayulita, which at that time was as quiet as Troncones is now. Along this coast, surfers—as they often do around the world—have played the role of pilot fish, seeking out places of great natural beauty and, unwittingly and often unwillingly, drawing the attention of an industry hungry for the same qualities but with a very different clientele in mind. Inevitably, there is tension between those who want to leave things in their raw, hippie perfection and those who want to endow this coast with Babylonian comforts: private pools, five-star meals, and steep prices. I confess a similar ambivalence: Whatever balance will ultimately be struck between the two camps, change is coming, and I am, I realize, one of its agents.

The inspiration for my journey was the Oscar-nominated Mexican coming-of-age flick Y Tu Mamá También. That very sexy road trip epitomized the special mix of heat and beach and atmosphere that I find a great antidote to a northern winter. Sure, Gael García Bernal and Diego Luna would not be my guides—I'd have to settle for my husband—but I was certain that I, like them, would find my own beach nirvana (or perhaps two). I plotted a course that would take me south along Highway 200 from Puerto Vallarta to Zihuatanejo, with a short detour north.

In 1999, Sayulita was the classic, unspoiled surf town, its name passed along in hushed whispers among adventurous beach lovers. The only people at the break that year were my fellow students from an all-women's surf camp, Las Olas, and a few local teenagers who put our skills to shame. When I turn up now, it's clear that the secret's out. Groups of sunbathing twentysomethings have staked their claim to the once empty stretch of sand, and the old ice-cream shop that doubled as an Internet café has been replaced by a Napa ValleyĐlike fine wine and cheese shop. Where a dozen surfers once bobbed in the water, I now count close to forty. Although the town retains much of its unmanicured charm, especially for the new visitor—the sandy roads remain unpaved, some favorite beachfront bars are intact—it feels decidedly more on the beaten path.