Free Shipping over $50 only to specific area

Hey all,

I have my own shipping trucks. For orders over $50 I want to offer free shipping but only to a 50 mile radius of my business. It doesn't have to be exactly 50 miles from my address, it can be a group of zip codes, but I can't figure out how to define this :(

Right now any purchase of over $50 gives the free shipping option. How do I limit this to only Chicago? I've been trying to define a specific shipping zone but it doesn't get any more specific than Illinois?

Thanks! this forum has been extremely helpful.

I've been looking for a solution to this but realize that I'm going to need to code this in myself somehow. This was possible with earlier versions of zen cart (addons like ZipShip)... so far nobody has made a publicly available solution for 1.5. I'm not good enough to do this myself but I'd definitely pay somebody to figure it out and customize it for me.

I have a list of zip codes that I'm willing to ship to with my own trucks. If the customer provided zip code is in my list they are eligible for the "free shipping over $50" at checkout.

Any takers? Message me if you're interested! $$$