Oklahoma State Highway 4 Oklahoma State Highway 4 State Highway 4, abbreviated as SH-4 or OK-4, is a designation for two distinct highways maintained by the U.S. state of Oklahoma. One of them serves as an important route through the suburbs west of Oklahoma City, while the other connects US-259 to the Arkansas state line west of Cove, Arkansas. SH-4 has no lettered spur routes. The two SH-4s were never connected. The Central Oklahoma highway was established in 1941 and gradually extended to its present extent between then and 2003. The Eastern Oklahoma highway was originally numbered SH-21, and was renumbered to SH-4 in
Oklahoma State Highway 156 along the highway. The entirety of SH-156 was once part of US-77. US-77 was realigned and SH-156 was assigned to the old alignment on March 1, 1965. On July 14, 1969, US-60/US-77/US-177 was realigned at SH-156's north end, necessitating a slight extension northward. No further changes have taken place since 1969. Oklahoma State Highway 156 State Highway 156, abbreviated SH-156, is a highway maintained by the U.S. state of Oklahoma. Spanning through the north-central part of the state, it connects the town of Marland, Oklahoma to US-60/US-77/US-177 in the north to US-77 in the west. It is the former alignment