Using Google Earth, it looks pretty flat around there, so you might be able to pick up the Hullman Approach/Tower controllers at KHUF, 38 miles (statute) from Robinson, if you have a good outdoor antenna mounted on a roof or tower. I used to live 20 miles from a Center transmitter and could get them about strength 4 inside the house without using an external antenna. So 38 miles seems reasonable with a good external antenna and nothing in the way (buildings/hills) ?
It looks like the closest Indianapolis Center transmitter would be in Terra Haute on 132.200 (low altitude to FL230) and 134.175 (FL240 to FL330). Basically the same distance as KHUF, maybe even located at KHUF (?), so you might be able to get them ?
I believe there is also a Kansas City Center transmitter located in Effingham which is only 43 miles (statute) west of Robinson, transmitting on 135.050 (FL240 to FL330) and 133.225 (FL340 and above). You might be able to pull those controllers in as well ?
Even if you can't get any controllers it would still be interesting to listen to aircraft only on the Center frequencies in that area. As a reference, below is a map showing the high altitude sectors in that area.
DJ