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 23 the current western terminus of SH-15 was made with what was then Farm to Market Road 1265 to Booker and TX-117 back to Oklahoma.) The connection to Kansas north of US-64 did not exist as a state highway prior to 1957; it first appears on the 1958 state highway map, also signed as SH-15. The highway is not shown as overlapping US-64 and US-270 to Elmwood. SH-23 is first shown replacing SH-15 on the 1959 map, implying the change took place in 1958. Again, SH-23 is not shown as overlapping US-270; it would not be shown as doing such until