Thanks for the ping. A petrified forest under water is very interesting. Maybe the land in that area rebounded after the glaciers melted at the end of the last ice age and then settled down again more recently.
It still seems amazing to me that the Great Lakes drain into the Atlantic via the St. Lawrence River, instead of into the Gulf of Mexico via the Mississippi River.
Lake Michigan drains a little into the Mississippi now. Engineers reversed the flow of the Chicago River & it became the Chicago ship & sanitary canal. You can guess the sanitary part.
I remember my college geology professor talking about the last iceage in 12,000 BC that leveled northern Indiana Illinois and Ohio down to about half way between Indianapolis and Louisville. I think he said there was some speculation that Lake Michigan could have been widened or deepened at the beginnng of the glaciation period.