He was the first European to make an overland excursion across northern Canada to the Arctic Ocean, specifically to Coronation Gulf, via the Coppermine River.

The basic theme of Hearne's three journeys is the Englishmen's ignorance of the methods of travel through this very difficult country and their dependence on First Nations who knew the land and how to live off of it.

Hearne planned to join a group of northern First Nations that had come to trade at Churchill and somehow induce them to lead him to the copper mine.

When the last First Nations left, Hearne and his European companions returned to the sheltered valley of the Seal River, where he was able to find venison, and reached Churchill on 11 December.

Second Journey: Since he could not control the northern First Nations, Hearne proposed to try again using 'home guards', that is, Cree who lived around the post and hunted in exchange for European supplies.

Here Northern First Nations (Dene) hunters gathered to hunt the vast herds of caribou migrating north for the summer.

... a young girl, seemingly about eighteen years of age, [was] killed so near me, that when the first spear was stuck into her side she fell down at my feet, and twisted round my legs, so that it was with difficulty that I could disengage myself from her dying grasps.

As two Indian men pursued this unfortunate victim, I solicited very hard for her life; but the murderers made no reply till they had stuck both their spears through her body ... even at this hour I cannot reflect on the transactions of that horrid day without shedding tears.

[7] Matonabbee led Hearne back to Churchill by a wide westward circle past Bear Lake in Athabasca Country.

After consulting some local chiefs, Hearne chose a strategic site on Pine Island Lake in the Saskatchewan River, 97 km (60 mi) above Fort Paskoya.

On 8 August 1782 Hearne and his complement of 38 civilians were confronted by a French force under the comte de La Pérouse composed of three ships, including one of 74 guns, and 290 soldiers.

The First Nations population had been decimated by European-introduced diseases such as measles and smallpox, as well as starvation due to the lack of normal hunting supplies of powder and shot.

[8] On 1 July 1767, he chiselled his name on smooth, glaciated stone at Sloop's Cove near Fort Prince of Wales where it remains today.

One of Wales's pupils, the poet Samuel Taylor Coleridge, made a brief notebook entry where he mentioned Hearne's book.

Hearne's journals and maps were proven correct by Sir John Franklin when he verified the discovery of the Bloody Falls massacre during his own Coppermine Expedition of 1819–1822.

In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, like a whale, insects in the water.

[10]Samuel Hearne's account of his exploration of the north, A Journey from Prince of Wales' Fort in Hudson's Bay to the Northern Ocean, originally published in 1795, was edited by Joseph Tyrell and reprinted as part of the General Series of the Champlain Society.