Until the Ngāti Wairangi of the West Coast were conquered about the year 1800, the expeditions sent across the ranges by Ngāi Tahu were war-parties, equipped to fight for the greenstone they wanted. The Ngāi Tahu used eight routes across the ranges, those from Canterbury and its immediate northern district being up the Rakaia River and over the Whitcombe or Browning passes to the Hokitika river; up the Waimakariri River and over Arthur's Pass to the Taramakau; up the Waipara and the Hurunui Rivers by Lake Sumner to Harper pass and the Taramakau; and (from Kaikoura) up the Waiau-uha and thence by either the Amuri pass to the Ahaura River and on to the Grey River, or by the Lewis Saddle down the Cannibal Gorge directly to the Grey River.