Chicagoland Area?
I'm a 20 year old guy who just became a nudist back in July of this year. I went to Sun Ray Hills in Burlington Wisconsin multiple times and loved every minute of it. So if you're new to nudism or haven't tried it yet but want to I'm here trying to encourage us young nudists to get together and have some fun in the sun. Also If you know of any indoor nudist friendly places like pools/spas/whatever please let me know because Winter is coming soon! :(
Turtle Lake in Michigan has indoor facilities. Check their website.
I'll echo Rockdad's comment about T.L. It's very nice too! You might also try Mazo Beach in Wisconsin. It's not too long a drive from Chicago and it's the best nude beach in the midwest.It might be the ONLY nude beach in the midwest