Two receptions

That seems confusing. I'd just have one. What if someone in KY wants to go to the IA one or vice versa?

I agree, just have one. Sometimes people have to travel for weddings - my entire extended family lives several states away from me, I'm only having one reception.

Don't combine the invites.

Our wedding is in Ohio (with my family) and his family is in Alaska.

We sent everyone invites to the wedding, but later, after our honeymoon, we'll plan the Alaska Reception and send out invites then to those up there.

Kentucky is really not even that far from Iowa.

Hello, fellow Kentuckian! I don't know where you are or where your Iowa crowd is exactly, but from Lexington to Iowa City is about 8 hours. Your current plans sound really confusing. You could 1. pick one place and have one wedding/reception, keeping in mind that some people may not be able to travel. 2. have one wedding/reception at one location, with a celebration of marriage later on at the second location, 3. pick a venue half way because that seems fair- a four hour drive for each side of the family. I really think finding a way to make one wedding and reception work would be easiest for all involved. I'm partial to option 3.

No, there's not. You studied your potential guest list and decided that you'd have your ceremony in the most populated area. If you want a second reception for those guests who weren't willing to make the trip, the best you can do is send them an invitation to a celebration of marriage.

I have to admit that I don't really understand the multiple reception dynamic following a wedding ceremony that I couldn't attend. In my day, you had a wedding and a reception. Those who could attend did attend. Those who declined, declined. End of story.

However, you're free to have a party hosting those who didn't attend your ceremony. Personally, I'd decline because...ehh, never mind.

How to word it? It's all over the internet -- search "invitations, celebration of marriage".