Few other secondary forest roads serve the lake sector for forestry and recreational tourism activities.

The main watersheds adjacent to Eternity Lake are: The Éternité Lake has a length of 9.0 km (5.6 mi) in the shape of a boat anchor, a maximum width of 2.6 km (1.6 mi), an altitude is 250 m (820 ft) and an area of .

The Éternité River has its source at Eternity lake (navigable length: 9.0 km (5.6 mi); altitude: 250 m (820 ft)).

The explorer Joseph Bureau, in his 1904 report on the township of Hébert, designated this body of water "le grand lac Éternité".

[2] The toponym "Lac Éternité" was formalized on December 5, 1968, by the Commission de toponymie du Québec.