Michigan's Name and the Lake French Maps Called Illinois

Michigan shares its name with a lake that old French maps called Lake Illinois and Lake Dauphin, before an Indian word outlasted them both. That word is said to mean “big lake,” or maybe “place for catching fish.” Nobody has proved which.

Lake Illinois, Lake Dauphin, Lake Michigami

Of the five Great Lakes, Lake Michigan was the last one the early mapmakers learned about. That’s according to Henry E. Legler’s 1898 Leading Events of Wisconsin History, which has a whole section on how the lakes and rivers got their names.

The old maps called it Lake Illinois, “after the tribe of Indians that dwelt on its southern border,” and Lake Dauphin, after the heir to the French throne. A Jesuit report of 1670–71 used “Lake Mitchiganons,” and a Paris map of 1688 labeled it Lake Michigami. Most of the early French maps preferred Illinois. Legler’s list of other names for the lake also includes Lake St. Joseph and the Latin Magnus Lacus Algonquinorum, the great lake of the Algonquins.

Big lake, or a fish trap

If you’re wondering why it isn’t Lake Illinois today, Legler doesn’t really say. He just calls it “the Indian word, which has outlived the European names.” What it means is less clear. It’s “variously interpreted to mean ‘fish weir,’ and ‘great lake.’” Some writers took it from mitchaw, “great,” and sagiegan, “lake,” and Legler says that “seems to be the most plausible explanation.” The fish-weir idea, he says, came from the shape of the lake.

If you look in the government’s 1905 place-name list by Henry Gannett, you get both readings and no pick: “said by some to mean ‘big lake;’ by others, ‘place for catching fish.’” A 1906 history of Michigan adds that the bands of Miamis who lived on the shore of the lake were called Michigamies.

The 1805 territory and the 1837 state

The United States made Michigan a territory on June 30, 1805, by splitting it off from Indiana Territory. In Thomas M. Cooley’s history, the lake was right there in the boundaries: the new territory’s southern line started at “the southerly bend or extreme of Lake Michigan.” Michigan became a state on January 26, 1837.

So the word beat a tribe’s name and a prince’s name, and two centuries after that 1688 Paris map, the books still couldn’t agree on whether it meant a big lake or a place to catch fish.

Sources & further reading

• Henry E. Legler, Leading Events of Wisconsin History (1898). The other names of Lake Michigan: Lake Illinois, Illinovik, Lake Dauphin, Michigami, Mitchigami, Mitchiganons, Lake St. Joseph, and Magnus Lacus Algonquinorum (p. 101); the last of the five lakes known to mapmakers, Lake Illinois “after the tribe of Indians that dwelt on its southern border,” Lake Dauphin, “Lake Mitchiganons” in the Jesuit Relation of 1670–71, the Paris map of 1688, the French preference for Illinois, “the Indian word, which has outlived the European names,” “fish weir” and “great lake,” mitchaw and sagiegan, the reading Legler says “seems to be the most plausible explanation,” and the shape of the lake (p. 102).
• Thomas M. Cooley, Michigan: A History of Governments (rev. ed., 1905). The Territory of Michigan set off from Indiana on June 30, 1805, and its line from “the southerly bend or extreme of Lake Michigan” (p. 140); the state’s admission on January 26, 1837 (p. 224).
• Henry M. Utley and Byron M. Cutcheon, Michigan as a Province, Territory and State, vol. 1 (1906), p. 90. The bands of Miamis on the shore of Lake Michigan “were called Michigamies.”
• Henry Gannett, The Origin of Certain Place Names in the United States (USGS, 1905), p. 207. “State of the Union and one of the Great Lakes. An Indian word, said by some to mean ‘big lake;’ by others, ‘place for catching fish.’”
• U.S. Census Bureau, state codes (2020). Lists Michigan’s permanent federal place-name record number (GNIS 1779789).