Honestly, for how much fresh water they hold, I’m surprised how small their watershed is.
That’s a surprisingly small watershed for such large lakes. Does it rain a lot or is it just accumulated over a very long time?
What tease! This great map begs for my close scrutiny. Alas! It will not bear it.
Edit: Here is a decent hi res map of the watershed. Boy, do I want to read every detail of that map you shared, OP. I’m going down the rabbit-hole!
Edit2: Another mid/low res map of the basin, but its awfully MS-Paint.
Edit3: found this digital version, but no better, really:
EditFinal: Here’s a depth and elevation profile that I found that’s clear and fairly detailed. I am too busy today to get further sucked in, but I could spend the rest of my day staring at these maps…
Fun Map Facts!
Lake Michigan resembles a penis.
More like one of those vibrators with the tickley things at the base of the shaft.
Awesome map!
But! Should Huron-Michigan count as one lake, or two, or three?