I did not find much about this here on LTHF. So I had better add it.
On Tuesday, I booked myself into They are both reachable via public transportation.
I chose the general admission for Barrington ($43.00)(3:00 - 6:45 pm) and the Iron Brewer admission for Oak Park ($63.99)(1:30 - 6:45 pm).
The chief reason I post this now is because these are 'Early Bird' prices which will go off-sale on Sunday, 16 June.
They are both very good beer festivals, although they are also quite different. You will glimpse many macro brewers at Barrington (because I think the city goes through suburban distributors). But this has the side effect of a distributor pulling out a keg or two of something that just was not moving {and is approaching its Pull-By Date} because suburban venues did not want to give it a tap handle.
The Oak Park festival is out in the open on the public streets. Non-attendees, including families with young children, are amidst the craft beer drinkers. Seven Generations Ahead, the sustainability non-profit organization, runs this in association with the Illinois Craft Brewers Guild, and its selections skew toward craft beers. {doh}
Go check the ticket detail pages I link to. Keep in mind these fests will go on rain or shine, and there are no refunds.