What was the dominant land cover plant here 10,000 years ago? Q33 of The Big Here Quiz

According to The Ancient Life of the Great Lakes Basin: Precambrian to Pleistocene by J. Alan Holman

In summary, by 10,000 years ago the forest vegetation in southern Michigan had become more diverse, with mixed forests of white and red pine, yellow and paper birth, aspen, oak, white ash, red and white elm, and blue beech.