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We could see muddy tire tracks on the dirt road in front of us where cars had previously driven into the river. But the water, which stretched at least 150 feet across the road, looked much deeper and wider than anything we had forged over the course of two family trips to Costa Rica's rugged Osa Peninsula.

With our 3-year-old son Zach in the back seat, my husband Gabe turned off the rental car. We had already driven for an hour over perilous gravel roads, starting on the peninsula's gulf side, and we had at least 45 minutes left to our destination on the Pacific. Turning back wasn't an appealing option.

Neither was flooding the engine. Besides stranding us in the middle of nowhere, rental insurance doesn't cover drowned cars. Soon, we struck on a reconnaissance plan. I would wade in and poke around to gauge the shallowest route.

But before I could get wet, a stroke of luck appeared in the form of a little gray car that zoomed around a bend on the other side of the river. Without hesitation, it took a diagonal path toward us and hooked a 45-degree turn midway through the river. The Costa Rican driver gave us a friendly wave as he passed by. Soon, we were back on our way across a place that remains blissfully — and sometimes strikingly — remote.

While much of Costa Rica has, in recent years, developed from a land of chill surf towns into Zipline Heaven, the wild still rules on the Osa, which juts into the Pacific like a hoof on the country's southern border. The peninsula harbors an estimated 2.5 percent of the biodiversity on Earth in a hunk of land that, at 700 square miles, is only slightly larger than Hennepin County.

I first visited Costa Rica as a college student in 1997 on a biology field study program that included a stint in Corcovado National Park, one of the Osa's chief attractions for adventurous travelers. Surrounded by enormous rodents, colorful birds and monkeys frolicking on the beach, I came to equate the Osa with paradise. Someday, I vowed, I would return.

The opportunity came nearly 15 years later, in 2011 — this time with my husband and our first son, then age 2. We left Minneapolis on a frigid February morning. Two days later, we emerged from a 12-passenger airplane into the searing heat of Puerto Jimenez, a dusty town on the protected coastline of the Golfo Dulce.

It quickly became clear that the Osa had managed to remain a remote oasis, even as the rest of Costa Rica has become a booming tourist destination. In 2016, more than 2.6 million visitors descended on the country, according to news reports. And while nature is a major draw, most follow well-worn routes to developed beaches and volcanoes.

Relatively few make it to the Osa, where the beaches are empty and the forests teem with creatures.

Lazy days

Nearly every year since our first family trip in 2011, we have settled into a midwinter routine that now includes our younger son Ben, born in 2013. Upon arrival in Puerto Jimenez, we squint against the bright shock of buzzing heat before grabbing our luggage off the airstrip and walking several hundred feet to pick up a rented 4x4.

From there, we stop at the town's grocery store, where we stock up on tortillas, mangoes and other basics before driving 20 minutes south to an off-the-grid rental house built a short walk from a mostly deserted beach. Any closer to the sand would violate zoning rules that limit development of Costa Rica's beaches.

Mornings start with the echoes of howler monkeys drifting through the relative cool of predawn. On lazy days, we play with hermit crabs, swim in the calm sea, and drive to town for gallo pinto (Costa Rican rice and beans) or ice cream before napping through the equatorial afternoon heat.

On more adventurous days, we strike off to watch local soccer tournaments or explore beaches, farms and forests around the peninsula. One favorite destination, about 30 minutes south, is the tiny hamlet of Matapalo, perfect for tide pooling, waterfall hiking and surfing on boards rented from a jungle lodge called Encanta La Vida.

On our first family trip, we kept driving south past Matapalo to the road's end, then took a sweltering hike along the beach to the serene La Leona Eco Lodge, on the southeastern edge of Corcovado. I had been eager to revisit the park for years. This time delivered a different experience, as 2-year-old Zach repeatedly fell out of bed onto the hard floor of our platform tent, sending screams into a long, still night past all the other sleeping guests, mostly newlyweds.

We decided to wait until the boys are older for a repeat visit.

But the park isn't the only place on the Osa to find adventure and spot wildlife. Our list includes sloths, coatis, leaf-cutter ants, three types of monkeys, scarlet macaws, toucans and more.

Jungle is the boss

At least once on every trip, the jungle reminds us who's boss. On our 2014 trip, when Zach was almost 5 and Ben had just turned 1, Gabe found a bark scorpion in a plastic bowl we had been using to hold some toys. He stood up, stricken.

"There's a scorpion," he stuttered. "Right there, where Ben was just playing!"

Luckily, Ben hadn't noticed it. According to our wilderness medicine book, the sting of the 3-inch-long arachnid can be deadly for babies. It's the kind of story that becomes routine on the Osa, much like the river crossing that temporarily halted our first cross-peninsula trek.

After retracing the other car's path through the river that day, we made it to our destination: a town on the Pacific called Drake Bay, where we spent the day hiking from idyllic beach to idyllic beach. On our drive back to Puerto Jimenez at the end of the day, we didn't hesitate at the river. We knew exactly which way to go.

Emily Sohn is a freelance journalist in Minneapolis.