“I’ve got frequent-flyer miles that I need to use within the next month,” announced my friend from Portland, Ore. “Not enough for an exotic trip abroad, but I want to go somewhere that feels at least a little foreign, where I can get a nature fix. Any suggestions?”

When it comes to travel, suggestions are no problem. “How about an ecotour of Baja?” I countered.

Ecotourism doesn’t immediately spring to mind when most people think of Baja, mainly because its most famous destinations are the teaming border city of Tijuana and the tourist-infested shores of Cabo San Lucas. But between the two, along more than a thousand miles of Mexico Highway 1, there are mountains, desert, sea and towns that call to travelers looking for a break from the rat-race and a return to nature.

It was obvious we didn’t have time to do the whole length of Baja and back in less than two weeks, so we began to whittle down our options. We decided to fly into Cabo San Lucas (it has the most flights from Los Angeles), rent a car and see how far we could drive up Baja.

From Cabo San Lucas, we headed for La Paz, capital of Baja California Sur. The downside of La Paz for the ecotourist is that it’s a big city, but the upside is that it is conveniently located to unique desert and ocean ecosystems and has guides and ecotour companies to get you there.

Probably Baja California Sur’s most famous natural wonder is the Sea of Cortés, forming an ecosystem of marine plants and animals so unique that Jacques Cousteau called it “The Aquarium of the World.” Underwater mountains and canyons are home to an impressive diversity of tropical and pelagic fish who survive on heavy plankton blooms nourished by huge amounts of circulating nutrient-enriched water.

But fish aren’t the only attraction; there are also marine mammals, sea turtles and hundreds of bird species. When the weather turns cold up north, gray whales migrate south to spend the winter in the protected lagoons of Baja; and more than 200 species of migratory birds head for the bays, islands, estuaries and lagoons.

On our initial venture into these rich waters — a daytrip out of La Paz — a 45-minute boat ride took us to our first stop, a sea lion colony. We donned flippers and snorkels and hopped in for a swim with some of these sleek, whiskered creatures. We then headed for a deserted beach on Espiritu Santo Island, where we swam in the warm water and ate fresh ceviche. This merely whetted our appetite, so we were delighted to find a company that offered an overnight excursion to the island, which we’d do on the return trip.

The next morning we decided to tackle the big drive from La Paz to Mulegé, about 300 miles. We hit the road early and took our time along the way, stopping in a couple of tiny towns and taking short hikes offroad to check out the desert flora and fauna.

Mulegé is my idea of a perfect laid-back Baja California town. Located between two hills covered in date palms, the town has a river bordered by a palm tree oasis, plenty of brightly colored bougainvillea bushes and a sleepy little square. We booked into the Las Casitas Hotel. In the heart of town, a courtyard festooned with foliage and flowers surrounded the spartan but squeaky-clean rooms and the popular restaurant.

We had planned to get our beach fix in Mulegé, and Bahía Concepción was clearly the place to get it. More than 25 miles long, the entire bay is a national marine preserve and is reportedly one of the cleanest marine systems in the world. Fishing in the bay is prohibited. Over dinner, a local man told us that Playa Los Cocos was one of the prettiest and least populated beaches near Mulegé. Limited camping facilities meant fewer people; and the calm, warm water glowed turquoise, thanks to the limestone of the surrounding cliffs. We spent most of the day on the peaceful beach sunning, swimming and reading, our hectic lives all but forgotten.

The next day, we resisted the lure of warm sand and sea and headed off to San Ignacio. A date palm oasis seemed to spring magically out of the arid desert, and we passed a large spring-fed pond and small river on our way to the town’s quiet square punctuated by one of Baja’s loveliest missions, San Ignacio de Loyola, completed in 1786. Walls of the mission are constructed of 4-foot-wide blocks of volcanic rock, which explains why the building has remained in its original state for centuries.

It was Sunday, so we sat in the square and watched local ranchers in cowboy boots and straw hats and children in their Sunday best pour out of the mission church. There was a buzz around the square as the kids played and ate ice cream while their parents gossiped with friends. It was a slice of Baja life far removed from luxury resorts and spa treatments.

While San Ignacio is worth the visit for the cultural aspect alone, there are a couple of special attractions for those who have more time. In the winter months, the nearby San Ignacio Lagoon is well known as a prime location for observing the gray whale migration. One multi-day guided whale-watching trip even includes a stay at a solar-powered ecolodge at the water’s edge. San Ignacio is also the gateway to some impressive cave paintings thought to be 6,000 years old. Tucked away in the Sierra of San Francisco, the sites have been distinguished by UNESCO as a “Patrimony of Humanity.” Because of their remoteness — and in an effort to control impact — a visit requires the services of a registered guide. Both the guide and permits can be obtained at the National Institute of Anthropology and History office next to the mission.

All too soon it was time to retrace our steps and head south. After an overnight in Loreto, which included a tour of the town’s mission and museum, we headed to La Paz for our overnight kayaking trip on the Sea of Cortés.

A motor launch sped us to our destination on Espiritu Santo Island, while a bilingual naturalist guide outlined our options for the next day and a half. We could snorkel, swim, kayak, hike or just veg out on the beach. All meals and cleanup would be provided by our cook; all we had to do was soak up the wonders of this amazing area. The red-hued sunset over the water was dazzling, and sleeping on the silent beach was beyond tranquil. We kayaked around a mangrove lagoon among egrets, herons and frigate birds. We snorkeled through schools of bright yellow sergeant major fish and shared the beach with red polka-dot sally lightfoot crabs. At dawn, we hiked by desert cactus to the top of a hill for a view of the rising sun and the Baja mainland.

Our road trip drawing to an end, we made our way back to Cabo. Avoiding the high-rise mega-resorts, we headed for the unpretentious El Delfin Blanco, just a few minutes’ drive from the more authentically Mexican town of San José del Cabo. The thatched-roof bungalows adjacent to the beach weren’t fancy; but for a casual, friendly and laid-back stay, the place couldn’t be beat.

For our last night in Baja, we had dinner under hanging straw lanterns on the tree-shaded patio of Tequila Restaurant in San José. A chile relleno filled with squash blossom, zucchini, corn and roma tomatoes preceeded a plate of local shrimp with plantains and black beans in tequila sauce, accompanied by a crisp Pinot Grigio — delish.

Just one thing left to do before heading home: an early-morning trip to the San José Estuary. A marshy lagoon covering almost 2,000 acres, it is the largest body of fresh water in southern Baja and is protected by Mexican law as a natural preserve and sanctuary for hundreds of species of tropical and migratory birds; many species of marine life; amphibians; reptiles; mammals and, of course, insects. A narrow finger of white sand separates the estuary from the Sea of Cortés, and at sunrise the sky turns brilliant shades of red and yellow as the air fills with bird calls.