From where I'm standing, in a meadow of dead grass and gnarled, leafless mopani trees on the banks of the Kapamba River, I can just make out the spotted tail of a leopard, whipping back and forth, somewhat menacingly, as he hunches on the horizontal branches of a sausage tree. Closer, a dozen hippos, each weighing about as much as a Ford F-150 truck, are splashing and snorting as they contend for the few remaining pockets of deep water in the parched river.

My guide, Fannuel Banda, barely registers the exhilarating – and, I can't help but remind myself, potentially deadly – wildlife all around us. Instead, he's down on one knee, studying a pile of giraffe shit. "See, it's flat. Brilliant!" says Banda, 33, speaking in the proper British accent that's a remnant of Zambia's colonial days, as he pokes the dung with his walking stick. "This stuff falls a long ways, so if it's flat that means it was not dry – there must be a lot of moisture. So even though animals are struggling to survive in the dry weather, we can tell the giraffes are getting good nutrition from the green leaves of these trees. These are very healthy giraffes."

Not that Banda, an expert tracker and naturalist, needs to examine the poop to know these giraffes are healthy: Two of them, majestic dark-spotted Thornicroft giants, native to Zambia, are standing less than 50 feet away, looking vigorous and curious, unbothered by our presence as they nibble on high branches.

It's almost noon near the end of October, the hottest and driest time of year in Zambia's South Luangwa National Park. We've been walking in 110-degree heat since sunrise, bushwhacking through crackling-dry mopani forests and along dusty hippo trails as we track lions, leopards, elephants, and other large game along the Luangwa River, the lifeline that runs the length of this 3,500-square-mile park, one of Africa's most isolated, undeveloped, and untouristed destinations. South Luangwa has no permanent settlements, save for a few wilderness lodges at the park's perimeter and a handful of bush camps in the interior. "Zambia is not a chic destination, not very well known," says Banda, who grew up in Mfuwe, a thatched-hut village bordering the park. "But that's what makes it special, because it's one of the world's wonders. It's as wild now as it's been for hundreds of years."

Unlike more popular destinations in Kenya, Botswana, and South Africa, where visitors mainly view wild game from the safety of Land Rovers, in South Luangwa, safaris are conducted mostly on foot. In four days of walking, I did not see a single person or vehicle or sign of civilization. But what South Luangwa park does have is wildlife – 4,000 elephants live in the park (down from around 7,000 two decades ago), along with lions, leopards, zebras, giraffes, baboons, buffalo, hyenas, wild dogs, jackals, crocodiles, 15 species of antelope, giant forked-tongue monitor lizards, snakes (including rock pythons and black mambas), and 350 types of bird, from rainbow-colored carmine bee-eaters to giant lappet-faced vultures that look frighteningly prehistoric as they watch you from the tops of baobab trees.

Walking safaris were pioneered in Zambia in the Sixties by adventurer Norman Carr, who wanted to share with his guests the experiences he had roaming Zambia as a game scout. Carr's family still operates a lodge near the park, and there are several other lodging options, from tent camps to luxe resorts. My trip was organized by CW Safaris, a Vermont travel company, in conjunction with the Bushcamp Company, which operates the spectacular Mfuwe Lodge – where I stayed the first two nights – and a group of rustic, comfortable bush camps, where I slept during the four-day walking safari.

At the Mfuwe Lodge, built around a lagoon next to the Luangwa River, elephants wander through the open-air lobby to munch on mango trees, and visitors and locals gather at the bar to drink Mosi lager and gin and tonics (another colonial relic), and trade stories about the day's sightings. On my first night, the guides talked about a local fisherman who'd been killed that day on the banks of the Luangwa. "It's foolish and dangerous to fish in the river with the hippos and crocs," a guide named Kelvin told me. "You would pretty much have to be mad or drunk to take the chance."

Banda says that when he was a kid, he learned to swim in the Luangwa with no fear of crocodiles. "The crocs were scared then, they would not bother you. But then someone built a crocodile farm on the river. When it went bankrupt, the owner released all the crocs, who had to then fend for themselves for food – they started attacking humans. It's sad because now our kids don't learn to swim."

Earlier that evening, Banda and I had spotted a massive female lion, not far from the park's main road, napping on her back next to the carcass of an elephant that had been snared in a trap. (Illegal elephant poaching is a growing problem in South Luangwa National Park, as it is all over Africa.) I asked Banda how much danger lions pose to humans. "Lions, like all predators, do their best to stay away from humans, so normally they will give you no problem," he said. "The only time there is a problem is if a rogue lion eats a human – then the whole pride will get the taste of human and must be killed."

When Banda was in grade school, a schoolmate snuck out of his dorm one night to visit his girlfriend and was killed by a lion. Several more lion attacks followed before rangers finally killed the entire pride. This wasn't the first lion to terrorize Mfuwe – in 1991, a 10-foot male cat killed several people before finally being shot by a hunter from California. The lion, nicknamed "Man-eater of Mfuwe," is on display at Chicago's Field Museum of Natural History.

Though South Luangwa is still an off-the-beaten-path destination, signs of a slow growth in tourism are evident around Mfuwe. Around sunset, you might experience the Zambian version of a traffic jam, when lodges take guests out to look for the nocturnal big cats. On my first "night drive," the road was clogged with Land Rovers lighting up the bush with spotlights 800,000 times the brightness of a candle, rolling up nose to nose to let tourists snap photos of a group of freaked-out hyenas or a lone leopard, stressed and panting as it tried to hide in a tree. I found the experience unpleasant and a little depressing, and asked Banda to turn back. He nodded. "My friend," he said, "I think you are ready for the bush."

We set out at daybreak in Banda's Land Rover, with no windshield and a cooler full of beer and Cokes strapped to the bumper. We were joined for the four-day expedition by two others: Mwase, Banda's assistant, and Moses, a ranger from the Zambian Wildlife Authority. A ZAWA ranger must accompany all walking safaris and must carry a weapon – a bolt-action .458 rifle, capable of killing a six-ton elephant with a single shot, should danger arise. Banda admits he's encountered some scary situations, like when he and a group of tourists stumbled into a herd of hippos or were charged by a massive bull elephant, but he says that in seven years of guiding, no one has ever gotten hurt and no animals have been shot. "I am a cautious man," Banda says, proudly.

Before our first hike, Banda laid out the rules: We walk single file, with Moses (and his rifle) in the lead, Banda in front of me, and Mwase watching the rear. "You need to show respect for the animals – that is the most important thing," he said. "Keep your distance, pay attention, stay quiet. The animal will tell you if he feels threatened, or if he is angry. You can move closer if the animal allows it, but you must do as the animal wishes."

Each day, we woke up at five, ate breakfast, then started walking at sunrise. This time of year, the whole region is parched and cracked, and many animals won't survive unless the rains come soon. Still, Banda says, there is plenty of nutritious food, even for a human. "You will never go hungry in the bush," he says. During a tea break, he sets off to prove it, foraging in the woods and returning with what he calls "a proper English breakfast": sausage fruit ("full of flavonoids"), a spongy-looking pod he calls monkey bread, and a delicate flower with white petals and a bright yellow center, like a fried egg. Banda's grandmother was a local herbalist, and frequently he points out plants that have been used by local tribes as medicine for centuries: sausage-fruit seeds for melanoma, and about a dozen plants that all seem to be some form of bush Viagra.

At first, being in the bush can overload the senses. The hallucinatory heat, the way the monotone gray-brown woodland seems to literally undulate with life: swarms of ants and mosquitoes; bushes alive with scrub hares, civets, mongooses, and even six-ton elephants, which walk so silently behind the trees that you might not notice them until they're 50 yards away. Most disorienting of all are the sounds – the buzzing, crunching, whizzing, and screaming – a relentless, rhythmic thrum that is unnerving at first, and loud enough to keep you from sleeping. But after a couple of days, I found myself getting used to the heat and the sounds, and noticed my senses getting sharper, able to pick out the urgent alerts of baboons warning of predators nearby, and even the soft thudding sound of leopards jumping out of the trees. I could soon spot well-camouflaged scrub hares and civets from a distance, and, with Banda's help, began to identify warblers and plovers and different types of waterfowl. During siesta time after a hike, I found it hard to nap or pick up a book – I spent my downtime scanning the riverbanks and fields with my binoculars, watching bush babies swing in the trees and zebras run and splash in the river.

One afternoon, at an idyllic tent camp called Chindeni, I was lying in the hammock outside my tent when a herd of elephants ambled up the riverbank in my direction. I'd been told to keep my distance from elephants, which can attack with little warning. But as the herd – six females, including a mother and baby – turned up the hill toward my tent, it was clear they could see me, and clear they weren't bothered. So I stayed still in my hammock as the mother paused to chew on branches and let her baby nurse. Four of the elephants got so close I could hear the rumbling in their stomachs – a main way elephants communicate with each other. At one point, the mother playfully wrapped her trunk around one of the stakes supporting my tent's platform, then lowered her head and leveled one huge brown eye at me. She stared at me for a good five seconds before letting go of the stake, snorting once, and walking off, with the other elephants marching behind her out of camp.

On our last night, at sunset, Banda drives the Land Rover across a rickety wood-and-rope bridge over the Kapamba, and pulls up on the bank of a small tributary for the customary happy-hour cocktails – what locals call sundowners. The sun sets fast in Zambia – it drops, really – but for a moment the sky is lit in electric purple and orange, and the bush is alive. Baboons scream in the trees, dozens of pukus graze in a nearby field, and a giant African fish eagle – Zambia's national bird – circles in the twilight. Banda says that after four days in the bush, he's looking forward to seeing his family tomorrow, and mentions that his older of two sons is named Elvis, after his grandfather. Tourists have told him that Elvis is also the name of a famous American singer, but Banda says he's never heard Elvis' music. So I dig my iPhone out of my rucksack and turn it on for the first time in four days. I find the most appropriate Elvis track I can think of – "Mystery Train" – and set the iPhone on the hood of the Land Rover. It's a perfect moment, thousands of miles from home in a place with no human development, no electricity, no cellphones, where nothing has changed for hundreds of years – and Elvis Presley blasting out over the savannah. As the song ends, and the buzz and hum of the bush fills the silence, Banda is quiet for a moment, sipping his Coke Zero. "I really enjoyed that, thank you," he says, politely. "But I think I prefer the sound of the bush."

More information: South African Airways flies from the U.S. to Lusaka, Zambia. The flight to Mfuwe is included in the trip. Vermont-based CW Safaris are experts in the area and work with the Africa's Bushcamp Company, which runs bushcamps and the Mfuwe Lodge, a world-class hotel, where elephants (and sometimes lions) roam the grounds. [$5,498; cwadventure.com]