Taken from the above website with deep appreciation.
HISTORY – DISCOVERY AND EXPLORATION
The Search for Land
As pastoralism spread in Canterbury, would-be runholders became explorers as they searched for ungranted land. Thus in 1851 M. P. Stoddart explored the upper Rakaia and Lake Coleridge region, and in 1855–56 J. B. A. Acland and C. G. Tripp went well up both the Rangitata and Ashburton Rivers. The author Samuel Butler was notable in this phase of exploration; in 1860 he explored the headwaters of all the great Canterbury rivers, saw the pass later known as Arthur's Pass but did not cross it, and, in company with the surveyor-speculator J. H. Baker, crossed the main divide via the Whitcombe Pass before J. H. Whitcombe. They were forced back while following a stream which flowed west. By this time, however, the mountains had been crossed by people other than Maoris, who, in fact, passed their information to the first European explorers. E. Dobson, in 1857, followed the Maori route up the Hurunui and over Harper Pass to the upper Taramakau River. Later the same year, L. Harper and S. Locke followed this route to the mouth of the river.

The search for grazing land also took men south. In 1861 Baker, with E. Owen, explored the region around Lakes Tekapo, Ohau, and Wanaka, and reached the top of Haast Pass. Julius von Haast was engaged to make a geological survey of the Canterbury province; urgency was soon given to his task by the hope of finding gold, prompted by the 1861 rushes in Otago. In 1862 he and A. D. Dobson went into the upper Waitaki River and past the lakes (Tekapo and Pukaki) to the peaks and glaciers beyond them. He named Mount Tasman, and also the Hooker and Mueller Glaciers, and saw the Murchison Glacier from the Mount Cook range, and attempted to cross the Sealy Pass to the West Coast. He also explored the Dobson and Hopkins Rivers from Lake Ohau. In the same year from the Wanaka-Hawea region, he crossed the Haast Pass to the West Coast. He found no gold, but caused some stir in European scientific circles by the evidence he found of extensive early glaciation.

The sheepmen were also important in opening Central Otago. Penetration to the lake country from the south began by C. J. Nairn and C. J. Pharazyn in 1852 who journeyed, with a Maori guide, from Invercargill via the Aparima and Waiau Rivers to Lake Te Anau. In the following year a runholder, Nathaniel Chalmers, similarly guided, went up the Mataura River to near present-day Cromwell and then by the Clutha to Wanaka and Hawea. Instead of pressing on to Canterbury via the Lindis Pass, as had been his intention, he returned down the Clutha River.

In the mid-1850s the Otago Provincial Government began to encourage pastoralists, and the pressure increased. The chief surveyor, J. T. Thomson, first attended to Southland, and then turned to Central Otago. In 1857, by way of the Shag Valley, the Maniototo Plain, the Ida Valley and the Waitaki River, he reached Omarama, and went from there to the peaks north of Hawea and Wanaka, naming one of the country's best-known peaks, Mt. Aspiring. Then he passed to Lake Ohau and the west side of Lake Pukaki. The sheepmen took up this country quickly; some had been there at the same time as Thomson. Their reach extended to the southern lakes by the end of the 1850s. D. Hay, an Australian, rowed a raft around Wakatipu in 1859 and explored the shores, learning of the existence of its northern arm. In the same year a large party including W. G. Rees reached Wanaka from Oamaru, followed the Cardrona River and the Crown Range south, and reached Queenstown via the Shotover and Kawarau Rivers. They went past the head of the lake to the Dart and Rees Rivers. D. McKellar and G. Gunn, two years later, explored the country between Lakes Wakatipu and Te Anau. The exploration conducted by the sheepmen was hardly systematic or accurate; they were more concerned with grazing land than with map-making. Between 1861 and 1864 James McKerrow followed them with an accurate survey.
Runholders' curiosity failed when they passed, as they inevitably did in pressing west, out of potential sheep country. But no country was unpromising to the gold seeker. After Gabriel Read's find in 1861, a series of rushes took men across Otago and into the mountains beyond. As well as gold, men looked for a west coast port with access to the interior, for quick communication with Australia. The north head of Wakatipu promised the best fulfilment for this chimerical hope. Charles Cameron in 1862 found a way across by the north branch of the Routeburn, and in 1863 P. Q. Caples went over Harris saddle to the Hollyford River. Later he followed the Hollyford to Martins Bay. In the same year James Hector went up the west branch of the Matukituki and over Hector Col to the Arawata and the coast near Jackson Bav. while Haast, following a Maori account, crossed the Haast Pass and followed the Haast River to the coast.

Meanwhile, during this period, boat parties were exploring south-western sounds and creeks for access to the interior. The Aquila party led by Captain Alabaster went from Milford to Martins Bay and the Hollyford River, discovering Lakes McKerrow and Alabaster. From Lake Howden, the party saw the rivers flowing east. A. Williamson with the Nugent, also in 1863, went up the Arawata from Jackson Bay and prospected without success around Haast and Cascade Rivers. Hector, using the Matilda Hayes, explored the Martins Bay – Hollyford – Lake Howden – Greenstone route, unaware of previous trips. There was enthusiasm in Queenstown, but the route west and the port remained unestablished. Nor was gold in workable quantities discovered in this wild region; the diggers who penetrated it had to rest content with extending the boundaries of knowledge.

The West Coast and its connections with Canterbury were almost all that remained. In these areas, explorers had to build upon the foundations laid by Brunner in the 1840s and Harper in the 1850s (as well as by some anonymous shipwrecked Americans who, with Maori help, walked from Jackson Bay to Nelson in 1857). In 1860 James Mackay opened up a direct Nelson-Greymouth route, using the Buller, Maruia, and Grey Rivers. A year later, J. Rochfort, following the course of the Grey, Ahaura, and Waiheke Rivers, crossed the divide to Doubtful River, a tributary of the Waiau. In 1862 there was a bridle path along this track; a year later it was used by sheep.

Gold in the mid-1860s stimulated Canterbury interest; in particular a serviceable route across the island was needed. This was discovered by Arthur Dobson in 1864, when he went up the Waimakariri and Bealey Rivers to cross the divide by Arthur's Pass, a route known to the Maoris but no longer used by them. The next year the West Coast gold rush set in; men poured over Harper Pass, and a bridle path and then a coach road were established over Arthur's Pass. The gold fever moved south, and prospectors with it into the remoter parts of South Westland, as far as northwestern Otago.