My local region of the SCCA a week ago announced the new proposed Palmer Motorsports Park in Palmer, MA. It's supposed to be an SCCA/club-only, non-spectator track.
The plans include a ~2 mile circuit with 12 (12!) buildings and a ~.5 mile driveway in, to keep things relatively far from residential area.
Here I propose a challenge for you all; make a track!
www.palmermotorsportspark.com is the website that should give you an idea of what to aim for in practicality.
I've made a
screenshot of a
Google Earth topographic map image overlay for you to edit with; use the actual thing to stitch together your own image if you like, I don't wanna have to do all of that by myself

.
Have fun!