Lake McConnell to have drained first into Lake Agassiz", an even larger lake to the southeast, "then into the Arctic Ocean via the Mackenzie River, then back into Lake Agassiz, and then back to the Arctic Ocean" at various times in its history. Either 8,300 or between 9,000 and 8,000 years ago, it divided to form Great Slave Lake and Lake Athabasca. These two and Great Bear Lake are considered its 'daughter' lakes. Lake McConnell Lake McConnell was a very large proglacial lake that existed in what is now Canada from 11,800 to 8,300 years ago. Other sources give starting and ending
Mackenzie River Ocean on 14 July 1789. The river he named "Disappointment River" would later be renamed in his honor. No European reached its mouth again until Sir John Franklin on 16 August 1825. The following year he traced the coast west until blocked by ice while John Richardson followed the coast east to the Coppermine River. In 1849 William Pullen reached the Mackenzie from the Bering Strait. In the following decades the North West Company established forts on the river, the precursors of present-day settlements such as Fort Simpson (formerly Fort of the Forks). A lucrative fur trade was carried out,