| Central Indiana Division |
IN & KY, USA |
| Central Kentucky and Southern Indiana Division |
IN & KY, USA |
| Cincinnati Division |
IN, KY, & OH, USA |
| Duneland Model Railroad Club |
Michigan City, Indiana, USA |
| Great Lakes Division of the TCA |
IN, KY, MI, OH, & ON, USA & Canada |
| Maumee Valley Railroad Club |
Harlan, Indiana, USA |
| Miami Valley Division |
IN & OH, USA |
| Michiana Division |
IN & MI, USA |
| Naptown & White River Model Railroad Club |
Indianapolis, Indiana, USA |
| NMRA Mid-Central Region |
IN, KY, NY, OH, PA, & WV, USA |
| NMRA Mid-Continent Region |
AR, IA, IN, KS, MO, NE, & OK, USA |
| NMRA Midwest Region |
IL, IN, KY, MI, & WI, USA |
| NMRA North Central Region |
IN, MI, & OH, USA |
| Ridge Model Railroaders Association |
Griffith, Indiana, USA |
| Three Rivers Division |
IN & OH, USA |
