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I awake with a start. In the predawn darkness, I strain my ears. Soft snorts and the sound of hoofs scuffling in gravel carry through my tent walls. Oh, no — javelinas! The Rio Grande Village campground here, in Big Bend National Park, is full of warnings about the hairy, piglike beasts. Officially called peccaries, the animals are known to snuffle around the campground in search of food, sometimes destroying tents and backpacks in the process.

Last night, I'd stashed my food in the campsite's metal storage locker. But I suddenly recall that I'd enjoyed a beer inside my tent before hitting the sack, and the can is still inside. Are some javelinas hoping to enjoy the last few drops? I quickly unzip the tent's door a few inches, shove the can outside, then zip it back up tight.

A thick silence now envelops the campground. I'm not sure if I imagined those snorts, or if javelinas aren't partial to stouts. Minutes later, I drift off to sleep as hundreds of stars wink overhead.

Big Bend, with more than 800,000 acres, is the nation's 15th largest national park, yet it is also one of the most remote and least visited. A mere 440,000 people head to these wild lands six hours west of San Antonio each year. That is a fraction of the 4 million who stop in at Yellowstone and Yosemite. But the park is every bit as impressive as its big-name counterparts. For Big Bend lies mostly within the Chihuahuan Desert, North America's largest desert and the most diverse in the Western Hemisphere, with rivers, mountains and its signature desert terrain. While most of the Chihuahuan Desert is in Mexico, experts say the portion encompassed by Big Bend beautifully showcases its rich diversity.

The expansive park is home to the Chisos Mountains, for one; it's the only national park to contain an entire mountain range. In addition, nearly 120 miles of the Rio Grande wind through the park. And, of course, there are miles and miles of desert. For visitors, this translates into a wealth of recreational opportunities such as hiking, backpacking, camping, rafting, canoeing and birding.

When I decide to explore the park, I determine it'll be most efficient to navigate it in sections. Big Bend's western portion is known as Castolon, an area famed for its Mule Ears and Chimneys rock formations, plus the Santa Elena Canyon. It also contains a historic district where U.S. Cavalry units once lived during the Mexican Revolution.

Big Bend's midsection is Chisos Basin. Part of the Chisos Mountains, the land here transforms into one of Douglas fir and quaking aspen, white-tailed deer and black bear. Popular destinations include the Window, a scenic overlook, and Emory Peak, the highest point in the Chisos at 7,832 feet.

The park's eastern segment, which contains Rio Grande Village, transitions back into desert. Top attractions here are a natural hot springs, Boquillas Canyon and the Rio Grande. Passport-toting visitors can cross the river into Mexico here via a port of entry to visit Boquillas del Carmen, a small tourist town.

Exploration in progress

After my inaugural night with the javelinas, I'm up before the sun, eager to explore Chisos Basin. My plan is an all-day hike that takes me to the top of Emory Peak, plus along the South Rim Trail, said to offer incredible views of Mexico. I'm barely on the road when a glance in my rearview mirror shows bold streaks of pink, lavender and gold brushed across an endless horizon. If this is any indication of what Big Bend offers, I'm in for one spectacular week.

My hike confirms that Big Bend is, indeed, one very special place. The minute I slip into the rugged Chisos Mountains, I'm surprised at every turn. The mountains' ancient, rocky flanks sport subdued cinnamon tones in the early hours, then sunny tangerine, pink and buttery hues as the sun arcs higher in the sky. Sometimes its peaks are fronted by delicate, golden grasses, other times by prickly, desert-hardened scrub.

I make the tough climb up Emory Peak, which requires some scrabbling by hand near the end, then nearly bump into a young black bear on the descent. My heart hammers at this close encounter, but four hikers who had crept up behind me thrill at the sighting. Later, rounding a corner, I come nose-to-nose with a white-tailed deer, then nearly step on a large, hairy tarantula.

In the afternoon, a cloudy sky smudges my view of Mexico from the South Rim Trail, but I'm still wowed by the green hills and rugged peaks that roll to the horizon and touch the sky. Even a wrong turn at day's end becomes a blessing when it leads me through lush Boot Canyon and a perfect view of the rock formation, reminiscent of an upside-down boot, that gave the canyon its name.

West to east

The next few days are a crush of amazing new vistas and experiences. Heading out of the mountains and into the Castolon area, I marvel at the wide swaths of land covered by mounds of pale, volcanic ash, remnants of the desert's early incarnation as a fiery land. And the park's iconic Mule Ears, I learn, are actually twin peaks of black igneous rock that once formed part of a volcano's core.

At Santa Elena Canyon, I navigate knee-deep mud to access the trail winding into the canyon's heart. But it's worth it to stand between rocky walls soaring 1,500 feet skyward from the banks of the Rio Grande — one wall part of the U.S., the other belonging to Mexico.

Hiking toward Balanced Rock north of the Chisos Basin, I tuck behind a young couple singing "Hakuna Matata." When we arrive, the woman and I gasp in unison as her companion immediately scrambles atop the highest rock, which appears precariously balanced, then strikes a victory pose. Despite our trepidation, we snap photos of him, then of each other, before I depart, "Hakuna Matata" running through my head.

Driving down to Rio Grande Village, elevation 1,850 feet, the temperature warms 10 degrees. A glance at my itinerary shows I'll be heading into Mexico tomorrow. On select days of the week, visitors can cross the Rio Grande to visit the Mexican town of Boquillas del Carmen. "It's a unique experience no other national park offers," a ranger tells me.

While you can often cross the shallow river on foot, $5 gets you a ride across via rowboat. Another $5 scores you a burro ride into Boquillas. While I can easily walk across the river and into Boquillas, which is less than a mile away, transport by rowboat and burro sounds infinitely more entertaining.

The following day, I arrive at the river shortly before lunchtime. I hear the food in Boquillas is good, and the margaritas even better. A gentleman slowly and rather clumsily rows me across the narrow, shallow river, where I pay for the burro ride and the services of a guide, Jesus. Jesus doesn't speak much English, but I know a little Spanish, so we manage.

Jesus first leads me on a quick tour of the small, brightly colored village, filled with women selling small handicrafts. Aprons, can cozies and other items proclaiming "No Mura!" (No wall!) are ubiquitous. It's not a surprising sentiment.

For decades, visitors to Big Bend regularly explored Boquillas. There was no need for a passport; you simply crossed the river. Then, shortly after the Sept. 11 terrorist attacks, the U.S. government closed all unofficial border crossings with Mexico. Without tourism to power its economy, Boquillas shrank. After pressure from locals on both sides of the border, U.S. authorities reopened the crossing in 2013.

Today, Boquillas is on the rebound. I help by purchasing a small wire sculpture of a roadrunner, Big Bend's signature bird, and a white apron with colorful stitching, both made by members of Jesus' family. Then I duck into tourist-favorite José Falcon's for lunch, where a few dollars nets me three bean tacos and a frosty margarita, all of which I enjoy on a spacious deck facing the Rio Grande.

Later, back at the river, the same man helps me into a rowboat for my 30-second return trip to the U.S. This time, however, he pulls me across instead of rowing.

"Is the current too strong?" I ask. "No," he chuckles. "I'm just too tired to row."

Bidding Big Bend adieu

My final day in the park is a hike out to the Hot Springs Historic District. Rock art etched by people who lived here thousands of years ago still decorates the white limestone cliffs, while 100-year-old buildings dot the acreage. The buildings were part of a small settlement that once featured a hot springs bathhouse.

Today, the bathhouse's foundation remains, tucked up against the Rio Grande, and 105-degree water regularly bubbles up through its sandy bottom. Although I'm warm after hiking here from the campground, I peel off my socks and shoes and slide partway in, joining a small but enthusiastic group of bathers. On the hike back, I pass an elderly couple toting colorful $1 inner tubes; they plan to float from the hot springs back to the campground, per a ranger's recommendation.

That night, tucked in my tent, a pack of coyotes begins howling under a plump yellow moon. The cacophony is a perfect soundtrack for this surprising land of ancient volcanoes and bubbling hot springs, opulent sunrises and snorting, stout-seeking javelinas.

Melanie Radzicki McManus is a travel and adventure writer. She lives near Madison, Wis. Find her online at thethousandmiler.com.