George,
Our club grooms by Lakewood Forest Preserve which is RT 176 and Fairfield road near Wauconda. You can park southwest of this intersection maybe one road south of 176 on Fairfield rd I think the name is Ivanhoe Rd.there are plenty of places to park just head west.
That's about all I know since we mark trials there. I don't ride in Illinois I keep everything in the western u.p. Good luck. bruce