^Looking south from the interchange at Interstate 70, August 2024.
Indiana State Route 243 runs north-south in an area south of Greencastle, in west-central Indiana. It connects US Route 40, Interstate 70, and Indiana State Route 42 to the Lieber State Recreation Area. The northern end is at US Route 40 in Putnamville, a tiny hamlet south of Greencastle; the southern end is at Indiana State Route 42 west of Cloverdale.