In 1776 Captain James Cook was dispatched by the Admiralty in Great Britain under orders driven by a 1745 act which, when extended in 1775, promised a £20,000 prize for whoever discovered the passage. Initially the Admiralty had wanted Charles Clerke to lead the expedition, with Cook (in retirement following his exploits in the Pacific) acting as a consultant. However Cook had researched Bering’s expeditions, and the Admiralty ultimately placed their faith in the veteran explorer to lead with Clerke accompanying him.
After journeying through the Pacific, in another west–east attempt, Cook began at Nootka Sound in April 1778, and headed north along the coastline, charting the lands and searching for the regions sailed by the Russians 40 years previously. The Admiralty’s orders had commanded the expedition to ignore all inlets and rivers until they reached a latitude of 65°N. Cook, however, failed to make any progress in sighting a Northwestern Passage.
Various officers on the expedition, including William Bligh, George Vancouver, and John Gore, thought the existence of a route was ‘improbable’. Before reaching 65°N they found the coastline pushing them further south, but Gore convinced Cook to sail on into the Cook Inlet in the hope of finding the route. They continued to the limits of the Alaskan peninsula and the start of the 1,200 mi (1,900 km) chain of Aleutian Islands. Despite reaching 70°N they encountered nothing but icebergs.
From 1792 to 1794, the Vancouver Expedition (led by George Vancouver who had accompanied Cook previously) surveyed in detail all the passages from the Northwest Coast and confirmed that there was no such passage south of the Bering Strait. This conclusion was supported by the evidence of Alexander MacKenzie who explored the Arctic and Pacific oceans in 1793.