Travel to Ruapehu, New Zealand's North Island: Volcanic peaks and jewel-coloured lakes

The lake is warmed by thermal energy coming from the magma chamber. In the 1950s and '60s folks would ski down to the lake, shed their outer garments and warm themselves in its steaming waters. Since then the lake has become more acidic. Swimming in it nowadays would not only warm you up, it would also give you a skin peel that might exceed the limits that a prudent dermatologist would prescribe.

It was this lake that caused New Zealand's worst rail disaster. On Christmas Eve in 1953, the dam at the far end of the lake collapsed, sending a huge pulse of water and volcanic debris charging down into the Whangaehu River. The surge took out one of the piers in the railway bridge over the river at Tangiwai and the bridge collapsed just minutes before the Wellington to Auckland express passed over. The locomotive and first six carriages fell into the river, with the loss of 151 lives.

There's a chill wind blowing when we leave, cross Dome Ridge and make our way back down the mountainside. Hari stops at the top of the first snowfield. It's reveal time for the plastic bibs. He shows us how to wrap them around our butts and fasten them to make a strap-on toboggan.

Hari goes first, sitting on a cut-off shovel which he uses to plough a track for us which we try to follow. It's hilarious, a shrieking, leg-and-arm flailing descent as we slide one after another in a nimbus of snow. There is still some walking across rocks but it's an express descent to the chair lifts and a hot chocolate back at the lift terminal.

The mountain gives its name to the much larger Ruapehu region, which lies at the centre of the North Island.It is south-west of Lake Taupo and is a rugged wilderness of volcanic peaks, lakes and not too many people. Population density is just 1.8 a square kilometre, about the same as Mongolia's, and far less than New Zealand's national average. What it does have is a list of extraordinary adventures second only to the South Island's Queenstown-Wanaka-Te Anau region.

The jewel in Ruapehu's crown is the Tongariro National Park, New Zealand's first national park, with World Heritage credentials both for its cultural and spiritual significance to the Maori people as well as its outstanding volcanic features. The park is home to the Whakapapa ski area, the country's largest, and also the Tongariro Alpine Crossing. It's sensational, a tough 19.4-kilometre walk across a scorched and brooding landscape shaped by volcanoes. The crossing passes the foot of Mount Ngauruhoe, used by director Sir Peter Jackson as the stand-in for Mount Doom in the film version of Lord of the Rings. The mountain is a good fit, "its feet founded in ashen ruin, its huge cone rising to a great height, where its reeking head was swathed in cloud", as described by the gothic pen of J. R. R. Tolkien.

Drawn by such a confluence of fact and fantasy, the Tongariro Alpine Crossing is being loved to death. About 70,000 hikers log the walk each year, the majority of them in summer, and parked cars clog the roadside for several kilometres from the track heads.

The hills and forests of the Ruapehu region provide some first-class mountain biking terrain, and one of the standouts is the trip along the Ohakune Old Coach Road operated by My Kiwi Adventure.

In the early years of the 20th century, the rail line between Auckland and Wellington was complete apart from a short section that ran through the formidable hills and deep river valleys on the south-west corner of Tongariro National Park. Passengers would disembark from one train and take a horse-drawn carriage to the next through the hills along the Ohakune Old Coach Road. The road fell into disuse as soon as the rail line was completed, but today this is a classic mountain bike trail.

Richard Faire is a former advertising executive who decided he had had enough of city living and chucked it in for a life in the wilderness, and no regrets. Today, with his wife, Stacey, he operates My Kiwi Adventure, a small-group adventure specialist with several options on the menu including stand-up paddle boarding and mountain bike trips, among them the Ohakune Old Coach Road. Mounted on 20-speed dual-suspension Merida mountain bikes it's a honey of a ride, roughly parallel to the route of the original railway line.

Parts of the track are little more than a handlebar width between the kauri and totara trees, which were never harvested, according to Richard, since the hills are too rugged to drag fallen timber out. The ride takes in some of the prodigious engineering feats along the old railway line, with the astonishing spider work of the Hapuawhenua Viaduct, snaking across a vast chasm, as the highlight. Born from springs and streams on the slopes of Mount Tongariro, the Whanganui is the longest navigable river in New Zealand. By the time it reaches the town of Taumarunui, it has been tamed, with gentle grade one and two rapids for the remainder of its journey to the sea

In this condition it becomes the country's finest canoe touring river, carving a passage through steep-sided green hills and terraced fields once cultivated by the original Maori settlers. A week-long, 145-kilometre canoe saga is feasible, but the three-day, 90-kilometre journey from Whakahoro to Pipiriki through Whanganui National Park is the scenic heart. At Pipiriki I board a snorting, grunting jetboat and head off upstream between sheer banks furred with moss for the 32-kilometre journey to the Bridge to Nowhere. In between high-speed schusses across mirror-smooth straights and over rapids where the water is raked into foam, Thomas, my guide and driver idles the boat in the current and tells us stories of the river and his exploits as a possum hunter, a lucrative trade in these parts.

The Whanganui was once one of the few conduits to Ruapehu's interior and a lively steamboat trade developed carrying cargoes and even tourists to the upper reaches. Several times Thomas points out huge iron eyelets anchored into the rock which the steamboats used to winch themselves upstream past shallow rapids. Maori would dig staves into the cliffs along the river to propel their canoes upstream. The holes left by their poles are still there, a line of punctuation marks etched into the rock, each one a couple of metres from its neighbour. Thomas points out rocks that mark the site of eel traps where Maori once fished. For Maori, this is a sacred river and the connection runs deep.

At the Mangapurua Landing we leave the jetboat and slog though dripping rainforest until suddenly a bizarre vision rises from the steep sided ravine of the Mangapurua Stream.

Constructed in 1936, the Bridge to Nowhere provided river access for farmlands carved out for servicemen returning from World War I. Just a few years after the bridge was completed, the Mangapurua Valley Soldiers Settlement folded, a victim of poor soils. Today the farms, the houses and the road leading to the bridge have been recaptured by forest but the bridge remains, a lonely monument to a dream gone wrong.

Back at the landing, Thomas tells me a story. According to Maori, the volcanic peaks of Tongariro National Park are gods, each one male or female. Mount Tongariro was married to the lovely Pihanga but when Mount Taranaki tried to seduce her a mighty war broke out. When it was over, Taranaki, the loser, fled to the sea and in his passage he gouged out the Whanganui River.

A few years before I did a hilarious trip along the Whanganui from Taumarunui with five Maori women in a waka, a canoe. To them this is not the Whanganui, it's Awa, "the river" and it's alive. Jackie, paddling in front of me, tells me about the river as a healer and finder of lost souls. It's a special place, she tells me, and when they leave the river they lose the thread from their lives. It was a voyage full of singing – theirs, not mine – but also one with tears.

In a landmark decision underlining that sentiment, New Zealand's Parliament recently recognised the Whanganui as a living entity, a person, in effect. In a resolution of the longest running land dispute before New Zealand courts, it underwrites the river's rights to health and wellbeing, with the power of the law to protect it from those who would do it harm. Those Maori maidens I paddled with all those years ago would be singing about that.

FIVE MUST DOS IN RUAPEHU

High tea in the Ruapehu Lounge, Chateau Tongariro, served with all the pomp and circumstance that this quirky relic from the 1920s demands. See chateau.co.nz/

Hike the Tongariro Alpine Crossing with a guide from Adrift. You'll get transport at both ends, an erudite explanation of the volcanic wonders and a few funny stories along the way. See adriftnz.co.nz

The Volcanic Explorer Scenic Flight with Mountain Air. Bird's-eye view of the craters, lakes, snow-capped peaks and steaming wonders of Tongariro National Park. See mountainair.co.nz

Paddle the Whanganui River. A journey for the heart as well as mind and body, and anything from a couple of hours to a multi-day camping expedition, either guided or DIY. See whanganuiriveradventures.com

The Tongariro River, which flows out of Lake Taupo on the north side of the national park, has some of the best trout fishing in the country, with easy access off Grace Road. Prime time is late summer.

TRIP NOTES

MORE

traveller.com.au/new-zealand

FLY

Air New Zealand has one-stop flights via Auckland from Melbourne and Sydney to Taupo, the closest airport to Ruapehu. See airnewzealand.com.au/

STAY

With a generous serve of log-cabin chic, the boutique Powderhorn Chateau in the groovy little town of Ohakune warms the heart with its smart rooms, a hot pool and a cosy restaurant strong on comfort food. See powderhorn.co.nz/

TOUR

The best way to get around is with a hire car, available from Taupo Airport.

Michael Gebicki travelled as a guest of Visit Ruapehu and Air New Zealand.