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The Pisa Range is a mountain range in Central Otago, in the South Island of New Zealand. It lies on the western shore of the man-made Lake Dunstan and overlooks the town of Cromwell. Its highest point, Mount Pisa, is .
The Pisa Range is the highest of the fault-block mountains characteristic of the Central Otago region, and one of the most distinctive land forms and ecological systems in New Zealand. The summit landscape is a broad, gently sloping undulatory dome, in places up to wide, falling steeply to the Clutha Valley floor. The Criffel Range forms part of the greater Pisa Range fault block mountain range that separates the Cardrona Valley from the Upper Clutha Valley.
Elevation ranges from approximately at the highest point. The aerial extent of the range is defined by the Clutha River / Lake Dunstan to the north and east, while the Cardrona River and Kawarau River lie on the western and southern boundaries, respectively.
There are two primary catchment areas which drain to the north and south. Luggate Creek flows into the Clutha River from the northern end of the range (at Luggate), while the Roaring Meg flows into the Kawarau River at the southern end of the range. Numerous alpine tarns occupy Cirque, the largest of which is Lake McKay at and elevation.
During the Cretaceous, regional uplift and erosion brought the Textural Zone IV schists to the surface, and an extensive low-relief surface was produced over the entire region. The tops of the ranges in many places are still represented by this erosion surface, often called the Otago Peneplain, though a more recent interpretation of the surface argues for it to be called the Waipounamu Erosion Surface. This is what gives rise to the broad smooth domal surface at the crest of the Pisa Range.
Schist tors or rock pillars, have been left exposed, potentially as remnants of more resistant rock resulting from the Waipounamu Erosion Surface. Though their formation is not well understood, they often occur as large rocky outcrops and are characteristic of the Central Otago landscape. John Turnbull Thomson and Alexander Garvie naming of the schist tor on Mount Pisa was so-named because of its similarity to the Leaning Tower of Pisa. The Obelisk or Kopuwai is a nearby similar schist tor on the Old Man Range.
Tertiary period sediments of the Manuherikia Group and Maori Bottom Formation were deposited by fluvial systems across the erosion surface. Once covering most or all of the Central Otago region, these sediments have been stripped off the rising mountain ranges and are now preserved only in the basins. Many of these sediments contained gold, leading to numerous gold rushes in Central Otago.
The Māori name of Mount Pisa is Taraputa, named for Tara Putakitaki, an early Kāti Māmoe chief.
Pisa is pronounced Pie-zer by the locals.
The name Criffel originates in Dumfries and Galloway, Scotland, where a number of the early settlers to the Otago region came from. The Criffel is a hill of , significantly smaller than its New Zealand eponym, Criffel Peak, at .
These gravels have been mined at the high fields of Criffel and Fatboys and along a fault line in the upper Roaring Meg. As well as the two major gold-bearing creeks there are terraces of stranded materials all round the skirts of the Pisa Range, in the Kawarau Gorge, along the Cardrona Valley (notably the Criffel Edge), Mid Run on the north face of the Criffel Range and along the Clutha terraces, especially at Gravelly Gully and around Lowburn.
Gold on the Criffel Range was discovered in 1883 by a small group of miners led by Cardrona miner, farmer, and musterer, John Halliday. The Halliday party struggled for two years before they managed to discover any significant finds at what was to become the Criffel Diggings (). By 1885 around fifty miners were working the diggings and between them, they had sold in the previous season. Mining continued into the 1890s with 27 miners taking 700 t oz (21.8 kg) in 1893. Mining ended in the first decade of the 20th Century. Around 2,000 t oz (62.2 kg) of gold was produced per year, although the figures are uncertain, as much of it went undeclared.
The Criffel Diggings goldfield was the last to be discovered in the Otago Region, some 25 years after gold was discovered in Gabriel's Gully. At around elevation, the Criffel Diggings are also one of the highest in New Zealand.
Sheep and cattle grazing continue to constitute the greatest land use of the Pisa Range (aerially), despite continued tenure reviews.
Most orchards and vineyards occupy the sandy gravels to the east of the Pisa Range, though several vineyards are located to the north near Queensbury and Cardrona.
The Waiorau Snow Farm borders the Southern Hemisphere Proving Grounds, a vehicle testing facility. Both venues use the same access road on the western flank of the Pisa Range.
On the eastern and northern flanks of the range some forest and shrubland remnants are present. The southern flanks (Kawarau) support extensive shrublands characterised by a high component of exotic species. The western (Cardrona Valley) faces are largely free of any woody vegetation. Some of the most extensive remaining woodlands are protected as scientific reserves in the vicinity of Luggate Creek and the Lochar Burn. Mid-slopes generally support short Tussock grass which, with increasing altitude, yield to a discontinuous band of snow tussock. High alpine cushionfields, fell fields, blue tussocklands and scree pavements cover much of the broad summit plateau. Many of the vegetation communities on the Pisa Range are botanically significant, including cushionfields on patterned ground, alpine tors, alpine Festuca tussocklands, snow banks, herb seepages, native shrublands and forest remnants.
As a result, some on the Pisa Range have been relinquished from farm grazing and are now managed by the Department of Conservation as public conservation land and reserves. Completion of further tenure reviews is likely to result in the entire range crest of the two ranges returning to full Crown ownership.
The long-term monitoring within the GLORIA network revealed just how slow recovery rates of degraded upland ecosystems on the Pisa Range has been. The crest of the Pisa Range was used for extensive merino sheep summer grazing, in combination with intermittent burning. This continued to 2012 when tenure review brought this detrimental land-use practice to a halt. The average soil organic matter recovery rate in the South Island high-country is estimated to be 35 years, but for heavily degraded areas, such as the Pisa Range, the rate is even slower than that with the recovery rate of cushion plants (and subsequent soil formation) being no more than 5% over a decade.
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