Hey another person turning 30 I just hit that marker in Dec. Welcome to the club. Well, almost anyway.

As for the 30 miler, Lise gave a good recommendation on the path. A good ride actually since you're at NMH is to head over to the path, start by Navy Pier, and head south. I'd go down the the museum of science and industry, which is on 55th street. There's a nice beach over there with a cool old building. Then turn around and come back up to your start point, which should give you about 15 miles. If you then take the path up north to Hollywood and come back down to NMH that should give you 30 miles, easily. You might not have to go all the way up to Hollywood.

Another possible 30 mile route is to ride up to Evanston, and ride up to the botanic gardens. My friend does that route. There's a bike path once you get into Evanston, though I'd have to research it a bit to find out where it starts, that takes you there. That whole thing RT with the ride back to NMH might be more than 30 miles though.

I don't know your comfort level of riding on the streets in Chicago, but you could plot out a route on that way to pass some cool places. Or plot some bars and make a pub crawl out of it (J/K).

If you're looking for a riding buddy that day, let me know.