Towards the middle of the eighteenth century, Native American reports of copper mines near a northern river prompted the Hudson's Bay Company to send missions of exploration into the remote northwestern interior of Canada. As they all failed, interest in the ore declined, until in 1767 Moses Norton, the son of the Hudson's Bay Company's first governor, now at its head, chose Samuel Hearne – an inexperienced twenty-four-year-old stranger who had only joined the HBC in 1766 – to undertake a series of overland expeditions. A young and fit man, Hearne had an excellent reputation for snowshoeing. No fewer than three attempts were however necessary to find the mouth of the Coppermine River and the exact location of the copper ore. A Journey from Prince of Wales's Fort in Hudson's Bay to the Northern Ocean in the Years 1769, 1770, 1771 & 1772, published posthumously in 1795, is Hearne's account of his ventures.

For his third expedition, Hearne imposed his choice of Matonabbee as his guide. A leading Indian, Matonabbee enjoyed great prestige among the Chipewyans and the Athabascan Crees and he was fully devoted to Hearne. Thanks to Matonabbee's help, and accompanied by a small party of Indians, Hearne reached the Coppermine River on 14 July 1771. The Indians then took him thirty miles south to one of the copper mines, where Hearne was terribly disappointed as he could not specify in what quantities copper was present.