The body of water is recognized as a Ramsar site[2] and as a Biosphere Reserve,[3] due to the presence of many marshes and wetlands that are frequented by waterfowl.

Approximately 12,500 years ago, the retreat of the glaciers at the end of the last ice age resulted in a vast basin filled by the Champlain Sea.

58% of the catchment area is located in the United States, 28% in Ontario and only 14% in Quebec (2.5% in direct tributaries, 0.07% in the littoral zone).

[4] The lake is located in the Regional County Municipalities of Nicolet-Yamaska, Maskinongé, D'Autray, and Pierre-De Saurel, in addition to the city of Trois-Rivières.

[5] The channel of the seaway that has been dredged has a maximum depth of 11.3 m. The lake was named by Samuel de Champlain following its passage on 29 June 1603, the day of the Saint-Pierre.

[10] Being the last freshwater basin of the St. Lawrence River and its geographical position, Lake Saint-Pierre has marked the history of French Canada in terms of the fishing industry, hunting, transportation including the St. Lawrence Seaway, pleasure boating, the settlement of surrounding lands, winter ice roads and ferries.

In places, the flow distribution in the lake due to[clarification needed] some stagnation of water near the banks, creating a silting.

In the area of Nicolet, the bed of the lake bottom contains an undetermined number of unexploded warheads from the centre of military fire[clarification needed] which was in operation from the 1950s to the 2000s.

On the north shore, between Maskinongé and Pointe-du-Lac, Highway 40 is a jetty protecting the land from rising or storm surges, at high tide or during major floods.