
I actually used algebra to scale the map up to fit the plywood. Strangely enough, I didn't really need to be so exact because if you measure Minnesota from its farthest north/south borders and farthest east/west borders, it is actually a square! It seems taller than wide, but Cook County juts out far in the east.
Now to start sawing with my little saw and then choosing seeds...
Thanks, Kristine, for the idea!