Illinois State Museum

French map of Illinois

Illinois River - Climate, Land, and Water

Changes Institute scientists use historical records to study environmental change that has occurred in Illinois since 1673. These records are a rich source of clues about geological, biological, and cultural changes.

On one side [of the Illinois River] you see prairies requiring only to be turned up by the plow, and on the other side valleys spreading half a league before reaching the hills, covered with walnuts and oaks; and behind these, prairies like those I have just spoken of.
— Pierre Delliette, 1702

There is a very great difference between this climate and that of Québec, where the cold lasts a long time, and a great quantity of snow falls; whereas here, as a rule, the snow remains but a very short time.”
—Julien Binneteau, 1699

The river is wide and deep, abounding in catfish and sturgeon. Game is abundant there; oxen, cows, stags, does, and Turkeys are found there in greater numbers than elsewhere. For a distance of eighty leagues, I did not pass a quarter of an hour without seeing some.”
— Louis Jolliet, 1674