Sunday, January 8, 2012

The Great Plateau of Michigan

The Northwestern Territories of the United States - From Dr. R. Brooke's General Gazetteer Improved, Johnson & Warner, 1812

There's a curious feature on old maps of Michigan and the Northwest Territory: a large plateau in the central Lower Peninsula with a ridge of mountains extending south through Indiana and Illinois. According to the Philadelphia Print Shop, where I downloaded these scans, the feature was first found in maps of the area from the late seventeenth century.

The Upper Territories of the United States - From Carey's General Atlas Mathew Carey, 1814

It's curious that the error remained in maps for over a century.


  1. I wouldn't necessarily call it an error... the highest topographical area in the lower peninsula is essentially where it is shown on the old maps (though rather crudely). Though there isn't a severe ridge that trends N-S, there are higher areas of elevation -- most likely a remnant of Pleistocene glacial activity.

    Here is a link to an elevational relief map of Michigan from the Forest Service -- you can sort of see a correlation between the old timey map and the colored relief map: