 By 1961, a new two-lane alignment of US 33 was established through Lakeview, Russells Point and to the southeast.Consequently, SR 366 took on the shape that it has today by being extended via a concurrency with SR 69 south into Lakeview, and the former routing of US 33 along the south shore of Indian Lake from that point east to its current eastern terminus at SR 117.Later in 1979, SR 368 was truncated from SR 117 to SR 366, leaving SR 366 the only route between those two highways.