What's your experience level? Are you a CFI building hours or just getting started?

When I was getting started, I wanted to be in Chicago and I had my sights set on Air Wisconsin and ACA. Look what happened there... Unfortunately, it's difficult to predict who will be where in the (not so) distant future. I hope that SKYW will stay in Chicago because that's where I am now, but there's no guarantee to that. As far as base stability goes, Eagle is probably more of a sure thing for ORD, but not necessarily a great place to go now if you want to be a captain anytime soon.

Good luck!

Oh, and I just checked. There are like 7 United flights a day including a few SkyWest and even 3 UA 737's. On top of that there are about 4-5 American Eagle flights, but they tend to be weight restricted a lot. In other words, it doesn't seem like it would be too hard to get from GRR to ORD.

http://timetables.oag.com/grr/