Mountains dominate large areas of the New Zealand landscape. About 60% of the South Island is covered by ranges with peaks over 1,500 metres high. Some peaks in the Aoraki/Mt Cook region of the central Southern Alps are more than twice this height.
Aoraki/Mt Cook, at 3,724 metres high, is New Zealand’s tallest mountain. It is 227 metres higher than its nearest rival, Mt Tasman.
The South Island also has:
The Southern Alps stretch for 500 kilometres, from Nelson Lakes National Park in the north-east to near the entrance of Milford Sound in the south-west. Made of greywacke sandstone in the east and schist in the west, they are by far the highest, longest, and most heavily glaciated chain of mountains in the country.
All of New Zealand’s peaks over 3,000 metres are in the Southern Alps. They also contain all the larger high snowfields (névés) and all remaining glaciers that extend down to the floors of major valleys.
In the west, the mountains end steeply and abruptly at the line of the Alpine Fault. To the east they spread further, with ranges and basins covering a large area of mostly high-country lands.
For thousands of kilometres, the Southern Alps are the only significant mountain barrier to the moist westerly winds of the Southern Ocean. This causes the range to generate the most extreme climatic conditions in New Zealand. There is a very high-rainfall zone to the west, and often drought-prone regions to the east.
South of the Southern Alps is the steep maze of the Fiordland ranges, which continue for 220 kilometres to the south-west corner of the island. These ranges gradually taper from high glaciated peaks in the north (Mt Tūtoko, 2,723 metres, and Mt Madeline, 2,536 metres) to summits between 1,500 metres and 1,000 metres, south of Dusky Sound.
The different geology of these ranges has produced strikingly different landforms. The very hard rocks of the sheer-walled valleys and fiords do not show the weathering and erosion seen in the Southern Alps.
In the north-east of the South Island, the high Inland and Seaward Kaikōura ranges splinter eastwards from the Southern Alps.
Explorer Julius Haast wrote of the Tasman Glacier, ‘As far as the eye could reach everywhere snow and ice and rock appeared around us, and in such gigantic proportions that I sometimes thought I was dreaming, and instead of being in New Zealand I found myself in the Arctic or Antarctic mountain regions.’ 1
The Inland Kaikōuras are dominated by the highest mountains in the country north of the Aoraki/Mt Cook region. These are Tapuae-o-Uenuku (2,884 metres) and Mt Alarm (2,877 metres).
The Seaward range includes the highest peaks near New Zealand’s eastern coast – Manakau (2,608 metres) and Te Ao Whēkere (2,590 metres).
In the north-west of the South Island are the Paparoa, Victoria and north-west Nelson ranges. They are not as high as other prominent mountain regions, but they contain New Zealand’s oldest sedimentary and volcanic rocks, its oldest fossils, its northernmost glaciated valleys, and some of the most dramatic landslides.
In the North Island, ranges with summits of 1,500 metres or higher cover about 20% of the total land area. Elsewhere are ranges of lower altitude or steep, dissected hill country.
The North Island has only three mountains over 2,000 metres, all of which are volcanoes:
There have been many minor ash eruptions from both Mt Ruapehu and Mt Ngāuruhoe over the past 150 years. More significant eruptions occur from time to time. The most recent were in 1974–75 (Mt Ngāuruhoe) and 1995–96 (Mt Ruapehu). Mt Taranaki (Mt Egmont) has not erupted in the past 250 years.
The most explosive and destructive eruption in the last 200 years was on Mt Tarawera (1,111 metres) near Rotorua in 1886. Between 108 and 120 people died as a result. The country’s most famous 19th-century tourist attraction – the pink and white silica terraces bordering Lake Rotomahana – was totally destroyed.
East of the volcanoes lies an unbroken mountain chain: the Tararua, Ruahine, Kaweka, Kaimanawa, and Raukūmara ranges. They extend from the southern end of the North Island up to East Cape, along the same south-west to north-east axis as the Southern Alps and Kaikōura Ranges.
These ranges are significantly lower than the volcanic mountains. The principal summits are all between 1,500 and 1,730 metres high.
For almost all of the 85 million years after New Zealand separated from the Gondwana supercontinent, the land did not have mountains. The present ranges only emerged within the last five million years, so they are relatively young, and very dynamic.
New Zealand has outstanding examples of the various processes that form mountains.
New Zealand straddles the boundary between the Pacific and Australian tectonic plates. As they collide, the plates push up the land, forming mountains.
The Southern Alps are one of the most rapidly rising mountain ranges in the world. The total uplift in the Aoraki/Mt Cook region during the past two to three million years could be as much as 20,000 metres. Dislocation of river terraces across the Alpine Fault shows that over the past 10,000 years, this uplift has continued at an average of 10 millimetres or more a year. Surprisingly, despite the rapid rise, there have been no major earthquakes in the central Southern Alps over the past 300 years.
Uplift rates elsewhere are more modest – about 5 millimetres per year along the west side of the Southern Alps and in the Kaikōura Ranges.
As well as uplift, there has been major sideways movement along the plate boundary. Over 15–20 millions years, this action has moved rocks apart by 480 kilometres: separate mountains, in the north-west and south-west of the South Island, contain rocks that were once in the same place.
New Zealand’s heavy annual rainfall has helped shape the mountains. More than 10,000 millimetres fall on the western side of the Southern Alps, south of Hokitika. Much of the alps, Fiordland and the north-west ranges receive over 3,200 millimetres. In the North Island the highest annual rainfall occurs on Mt Taranaki (Mt Egmont), including a record 844 millimetres in 48 hours in 1967.
While plate movement is pushing the mountains up, high rainfall is wearing them down.
New Zealand’s mountains and the Chilean Andes are the only significant barrier to the moisture-laden westerly winds that circle the Southern Ocean. On reaching the mountains the air rises, dropping rain on the west coasts.
In the Southern Alps, rock is split by the stresses of rapid uplift, and temperatures often shift from freezing to thawing. Combined with high rainfall, this results in very rapid rates of weathering and erosion. The results of this vigorous erosion is apparent in the widespread cones of eroding scree and the expanses of boulder and gravel that make up the beds of the larger rivers.
Erosion has also produced the eastern expanse of the Canterbury Plains and the high coastal hills (up to 680 metres) of South Westland. Both areas have been formed by ice-age glaciers and rivers carrying eroded debris to the coast.
In a dramatic scene of alpine erosion, a huge rock avalanche broke away from the High Peak of Aoraki/Mt Cook in December 1991. About 14 million cubic metres of rock and ice fell onto the surface of the Tasman Glacier, reducing the height of New Zealand’s highest mountain by 10 metres. It also damaged the mountain’s elegant profile.
For much of the past two million years, the rising Southern Alps and Fiordland mountains were buried under huge ice-age glaciers up to 1,000 metres thick. These glaciers filled valleys as far as 100 kilometres east of the main divide of the Southern Alps, and extended westward beyond today’s coastline.
The glaciers carved out the sheer-walled, U-shaped valleys and fiords of Fiordland, and the deep (up to 444 metres) southern lakes. In the Southern Alps the legacy of ice age glaciers remains in the deep, ice-straightened valleys, large lakes and vast deposits of rocks, debris and gravels.
The most common ‘parent rocks’ from which the mountains originate are a sandstone known as greywacke, though there are mountain regions of schist, granite and other hard rocks.
The Southern Alps are formed from 100–300 million-year-old sedimentary rocks. These are greywacke that contains narrow bands of siltstone in the east, grading into schist west of the main divide. Greywacke sandstones also provide the ‘parent rocks’ in the Kaikōura ranges and North Island axial ranges.
The mountain ranges that form the backbone of New Zealand are made of ancient greywacke, which is being rapidly uplifted and eroded. Boulders in many of the rivers are made almost entirely of this rock. If you identify a grey rock as greywacke, there is a good chance you will be correct. Much of the sand on the beaches is made of tiny fragments of greywacke – which is why most New Zealand beaches are grey.
Fiordland’s hard, crystalline rocks (granite, gneiss and diorite) are far more resistant to erosion than the greywacke ranges. This has resulted in a sharper topography of sheer-walled valleys, fiords and chiselled peaks.
Granite and gneiss also feature in the ranges in north-west Nelson. Here you will find New Zealand’s most diverse topography of ridges and crests, and the only sizeable areas of alpine karst (limestone and marble) terrain.
In the North Island the distinctive shape of the volcanic mountains is a result of thick lava flowing out of vents and forming high cones.
There are more than 600 species of plant that occur above the treeline, and 93% of these are endemic – they are found nowhere else in the world.
There are also many unique plant genera, or groups. In the alpine and subalpine category are Raoulia, Haastia, Hectorella, Dolichoglottis and Leucogenes. Other groups, such as Aciphylla, Anisotome, Brachyglottis, Celmisia, Craspedia and Hebe, have only a few species that are found in other countries.
Different types of plant grow in different zones, according to altitude.
The flanks of the major ranges are covered in dense native forest up to the treeline (the forest’s upper limit, around 1,200–1,600 metres), except where it has been destroyed by fire, landslides or other natural events. Beech forests dominate the drier eastern ranges. A blend of conifer, beech and broadleaf trees is more common in wetter areas.
A dense tangle of shrubs grows in a narrow band above the treeline, and at the heads of valleys – especially where there is higher rainfall. Beyond this, or at beech treelines in drier eastern regions, there is often a zone dominated by tall tussock grasses.
Tussock gives way to rock and low-growing cushion plants, and then to herbfields, with exposed rock.
Many native alpine plants have white or, less often, yellow flowers. Even the plant groups that bloom elsewhere in a range of colours (Ranunculus, Myosotis, Gentianella), usually produce white or yellow flowers
The likely explanation is that New Zealand alpine plants were mostly pollinated not by birds but by beetles, flies and moths. These are not attracted by bright colours, so the plants did not evolve to produce colourful flowers.
The comic and colourful native kea (Nestor notabilis) is the world’s only mountain parrot. The tiny, elusive rock wren (Xenicus gilviventris) is the only New Zealand bird that spends its entire life above the treeline. Both kea and rock wrens are found only in the South Island mountains.
Other unusual native animals of New Zealand’s mountains are hard to find. They include:
Invertebrates are often the most visible animals above the treeline – on warm summer days, the grasslands and herbfields are alive with grasshoppers, moths, beetles and flies.
Mountain ranges are the main habitat for many animals brought to New Zealand and now living in the wild. Usually found in the dense forests, they also tend to be elusive, even when present in large numbers. Among the larger animals are several species of deer, feral goats and pigs, Austrian chamois and Himalayan tahr (the last two being confined to South Island areas). The smaller animals include mice, Norway rats, ferrets, stoats, weasels, feral cats, Australian brush-tailed possums, rabbits and hares.
All these animals are now classified as pests. Over the past 150 years their ecological impacts have altered the character of New Zealand’s mountains. They have greatly reduced both the diversity and number of native birds. This in turn results in fewer plant seeds being dispersed. The vegetation is further reduced by browsing animals, contributing to erosion. Their impact has been greater than that of floods, snowfalls, landslides, fire, volcanic eruptions and the clearing of forest for farmland over the same period.
Rising towards the realms of Ranginui the Sky Father, remote from human settlement, mountains loomed over the Māori world. They were places of great awe and spiritual presence.
Nearly every range and prominent peak in the country is linked to local tribal identity and mana. Special reverence is given to the higher peaks such as Tongariro, Ruapehu, Taranaki and Hikurangi in the North Island, or Aoraki in the South Island. A Māori proverb states: ‘Mehemea ka tuohu ahau me maunga teitei’ (If I should bow my head let it be to a high mountain).
Some Māori were highly skilled at travelling in mountain regions, and often were valuable guides for early European explorers.
Horonuku Te Heuheu, paramount chief of the central North Island Ngāti Tūwharetoa tribe, gifted the sacred Tongariro mountain to the Crown in 1887. This formed the basis of New Zealand’s first national park. He observed, ‘Tongariro is my ancestor, my tupuna; it is my head; my mana centers around Tongariro; my father’s bones lie there today.’ 1
Māori traditions told of how mountains were formed – sometimes along similar lines as European scientific explanations. For example, they believed that this mountainous land had not always been here, but had been fished up from the bottom of the sea.
They also compared the shaping of landforms with the transformation of a tree into a carving or canoe. One name for Franz Josef Glacier was Kā Roimata o Hine Hukatere – the tears of the avalanche girl.
In the 19th century few Pākehā New Zealanders climbed mountains for the sake of it. Most journeys to mountain regions were in search of gold or other minerals, or to find routes for roads and railways.
A coach road via Arthur’s Pass was opened across the Southern Alps in 1866, but it was 46 years before anyone climbed Mt Rolleston (2,275 metres) – the highest peak close to this trans-alpine highway.
Although by 1880 most major mountain valleys in both islands had been explored and the passes between them crossed, many prominent New Zealand mountains were not climbed for another 30 or 40 years.
Europeans climbed the North Island volcanoes early on – the first ascents of Mt Taranaki (Mt Egmont) and Mt Ngāuruhoe were in 1839. But Ruapehu, the highest North Island mountain, was probably not climbed until 1886.
Because of early interest from overseas climbers, first ascents were made sooner in the Aoraki/Mt Cook region than elsewhere in the South Island. The first ascent of Hochstetter Dome (2,827 metres) was in 1883. Aoraki/Mt Cook was first scaled on Christmas Day 1894, after several close attempts over the previous 12 years.
In general, New Zealanders have not tried to build permanent settlements above an altitude of 600 to 700 metres. The few genuine mountain villages are mostly by-products of construction projects – roads and railways (National Park, Arthur’s Pass), hydro-electricity schemes (Tekapo, Twizel) or alpine tourist and recreational attractions (Aoraki/Mt Cook, Whakapapa).
Along the eastern side of the Southern Alps, the boundaries of high-country sheep stations reach well into the headwaters of most major valleys. These farms often extend to altitudes of 1,500 metres or more.
From the 1880s Aoraki/Mt Cook, Milford Sound and the North Island volcanic mountains were promoted as scenic attractions. As roads and accommodation improved, more people visited these and other mountain regions.
In the 2000s, about 500,000 people a year visit Aoraki/Mt Cook, and up to 2,000 a day travel along the dramatic highway through Fiordland’s Darran Mountains to Milford Sound. Limits on the number of visitors have been considered at some tourist spots, including the Fox and Franz Josef glaciers.
For those who enjoy more remote mountain adventures, New Zealand offers world-class facilities including thousands of kilometres of tracks and marked routes, and over 800 back-country huts. There are excellent maps and guidebooks on most areas, and many opportunities for tramping (hiking), mountaineering, hunting, fishing, kayaking and mountain biking.
The network of national parks is mostly in mountain regions. By 1900, national parks had been created on Mt Tongariro and Taranaki (Mt Egmont). Large areas of South Island mountain lands had also been set aside for national parks at Aoraki/Mt Cook and Arthur’s Pass. Almost a million hectares was reserved in Fiordland in 1905.
By 2007, there were five national parks spread along the Southern Alps – Nelson Lakes, Arthur’s Pass, Aoraki/Mount Cook, Westland Tai Poutini and Mount Aspiring. Along with Kahurangi, Paparoa and Fiordland national parks, they form a continuous tract of protected mountain lands extending the entire length of the South Island.
In the west of the South Island and in Stewart Island, national parks extend from the mountains to the sea. West Coast poet Peter Hooper writes of this region being ‘as beautiful, as mysterious, as rich in elemental spirit as any left upon earth’. 1
Because of these national parks, mountain landscapes enjoy a high level of protection. But in the drier eastern South Island ranges, there are large areas that are not protected.
Especially in the South Island, mountains have been a dominant theme for New Zealand painters. Early Pākehā artists often depicted mountain landscapes, and 30 of the 49 South Island paintings in Christopher Johnstone’s 2006 book Landscape paintings of New Zealand feature high, snowy mountains, despite the fact that few South Islanders live in such areas.
Mountains have also been important in contemporary photographic books of the New Zealand landscape, like Craig Potton’s New Zealand under the southern sky (1993) or Andris Apse’s New Zealand landscapes (2006). As Potton wrote in 2005, ‘[m]ountains overspread the horizon, calling into question our sense of scale, our sense of place, our sense of ourselves’. 2
In New Zealand writing, mountains are more likely to be a backdrop, with the focus on human lives and interactions. However, there are some cherished works in which mountain regions play a bigger role. Poems include James K. Baxter’s ‘High country weather’ and Denis Glover’s ‘Arawata Bill’. Among significant novels set in the mountains are John Mulgan’s Man alone and Maurice Shadbolt’s Season of the Jew.
From the earliest attempts at serious mountaineering in the 1880s, and the first issue of the New Zealand Alpine Journal in 1892, there has been a steady stream of mountaineering and wilderness non-fiction. Many guidebooks have been published in the last two decades, and much New Zealand non-fiction has been written about mountains.
Coates, Glen, and Geoffrey Cox. The rise and fall of the Southern Alps. Christchurch: Canterbury University Press, 2002.
Knox, Ray, ed. A thousand mountains shining: stories from New Zealand’s mountain world. Wellington: Reed, 1984.
Logan, Hugh. Classic peaks of New Zealand. Nelson: Craig Potton, 2002.
Mark, A. F., and Nancy M. Adams. New Zealand alpine plants. Rev. and updated ed. Auckland: Godwit, 1995.
Potton, Craig. Tongariro: a sacred gift: a centennial celebration of Tongariro National Park. Nelson: Lansdowne Press and Craig Potton, 1995.
Wilson, Jim. Aorangi: the story of Mount Cook. Christchurch: Whitcombe & Tombs, 1968.