From the moment we began ascending the hillside I could tell my walking companion, Suze, was nervous. Beneath her long ginger fringe her eyes were wide, on high alert. After years of solo hiking, I was feeling a little apprehensive, too. Would we get on? Would she refuse to walk the distance? Would she be happy carrying all our kit?

Suze, I should mention, is a pony. But not just any pony. She’s one of a semi-feral herd that has roamed the mountainous regions of Wales since as far back as 1600BC. Said to be relatives of the prehistoric Celtic breed, Welsh mountain ponies were traditionally used to transport goods to market, plough fields and work as pit ponies in the mines, not for riding. Their once widespread use is the reason thousands of miles of bridleways were cleaved across the countryside, creating a network of rights of way that exist to this day.

Despite Suze’s initial apprehension, as we began our overnight adventure together among the Powys hills, it was obvious she and her kind are made to be in this environment. Hardy, with thick coats, a sturdy gait and surefooted, they can survive year-round on the hills without help from humans.

But there is a problem: they are dying out. With technology and machinery replacing their traditional roles, coupled with the costs involved in having them chipped, registered and issued with passports, many farmers who traditionally manage and breed them say they are not commercially viable. Where once there would have been thousands, now there are fewer than 500.

That’s why I was bimbling alongside my new four-legged friend, after a day’s horsemanship training at newly established Hooftrek. Set up by 77-year-old pony whisperer Graham ‘Will’ Williams, he hopes it will bring tourists to this rather neglected part of Wales, often overlooked in favour of the nearby the Brecon Beacons, and give the ponies a value. So far he has arranged ownership and care of 16 ponies, including a large number of colts who – with no breeding taking place – would have likely been sold off for food.

“We looked to our neighbours in France, Italy, Portugal and Morocco – who had a similar problem with their donkeys in the 1970s when their jobs were replaced by machines,” said Will when I arrived at his farmhouse above the village of Erwood, just south of Builth Wells, to be matched with my pony. “They realised they are ideal pack animals – and could be used to carry equipment on expeditions. It’s now a massive industry in those countries and we believe we can replicate that here.”

And so I was in the first group of pack pony trekkers to trial the experience. The plan was not too ambitious –a 5km self-guided walk bound for Pam’s Place, a patch of land high on the hills where we could tie up our ponies and pitch a permitted wild camp under the stars.

“Remember that the ponies are part of your team,” said guide and pony trainer Lou. “You want them to be comfortable, too, so the panniers must be of equal weight and you must take on the role of lead animal, reassuring them that you are in control.”

We spent several hours getting our hands dirty: grooming, tacking (that’s putting on their trekking accessories), and leading them on a short walk to learn how to handle our newfound teammates. Then Lou pronounced us ready.

As she, Will and the farmhouse faded into the distance, and Suze and I navigated our first gate without incident, I began to relax. When walking alongside a pack pony, slow travel is the order of the day. I recognised which type of terrain she preferred to step on and changed my route accordingly; I noticed her penchant for chowing down on thistle flowers (and timed it so I could indulge in my fondness for snacking on wasabi peas, simultaneously); and respected her fear of stream crossing, so instinctively took the lead to show her the way.

In adjusting my speed, my walk became an almost mediative experience. It gave me time to notice the landscape. Around me spread out a boundless patchwork of green and yellow, rising to upland plateaus. I identified rustles in the foliage that alerted me to the presence of red kites, swifts and whinchats. I had time to stop and spy the Pen y Fan range in the Brecon Beacons, which appeared as just a bluish watermark in the distance, and found myself soothed by the soundtrack of the soft padding of Suze’s hooves as she trampled over huge patches of unwieldy bracken.

That’s another reason we need to protect these ponies, according to Donna Udall from the Centre for Agroecology, Water and Resilience at Coventry University, who is working with Hooftrek to lobby the Welsh parliament to protect these ponies.

“They breakdown the vegetation differently to cows and sheep, which results in less overgrazing and less erosion of the soils, which helps keep the carbon safely in the ground,” she said.

Udall also pointed out that their dung fertilises the soil and supports around 250 different species of insect. “And all with the bonus that they don’t need petrol – unlike a tractor with a grass-cutter – so they are an environmentally friendly way to help maintain access to the land.”

I thought about this as we continued on our steady walk, listening to the hum of bees and mesmerised by the number of beetles scampering amid the wildflowers. Soon we were at the Scots pine trees that marked the start of Pam’s land. We’d made it.

I set about unpacking the panniers, and released Suze into an adjacent paddock to graze. As our small group put up the tent and made dinner, we shared satisfied looks from having achieved this happy state all by ourselves. That night, snuggled in my sleeping bag, I heard the whinnying of Suze outside and felt reassured by my new camping companion’s presence.

The morning broke with sunshine. As I cleaned Suze’s hooves, fed her hay and packed up the camp, she seemed as calm as I did, trusting my voice and allowing me to do what was needed.

Lost in the landscape once more, we made our way home so that she could rejoin her herd. And though it was also time for me to go back to my solo walking, I like to think I’d learned something from my time with Suze: to allow myself to walk slowly; to appreciate the trails that both her and our ancestors created to enable us to wander unhindered; and to always make time to smell (or in her case eat) the flowers.

• Hooftrek offers guided itineraries in the Welsh hills with its semi-feral herd, as well as day trips, bespoke expedition packages and self-guided options, starting at £290, including pony training and equipment, exclusive wild campsite use (with permission), all kit, basic food, route planning and 24/7 backup