 The highway was extended to Okmulgee on April 13, 1942, bringing it to its current extent.Other than minor realignments and establishment of the Loop route segment, the highway has undergone no further changes since 1942.State Highway 56 Loop (also known as SH-56 Loop or more commonly, Loop 56) is a bypass route around the northeast quadrant of Okmulgee, starting from US-75 in the north of Okmulgee, running in an arc east and then south, and connecting with US-62 east of the city.