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 151 while on the east side is the Arkansas River. After crossing the dam, the route ends at US-64/US-412 at another trumpet interchange, west of Sand Springs. Keystone Dam was completed in 1964. The dam was first shown as a state highway on the 1965 state highway map. No SH-151 shield was shown on this map, however; presumably it was omitted for space reasons. The highway would remain unlabeled on the official state maps until the 2008 edition. Oklahoma State Highway 151 State Highway 151 (abbreviated SH-151 or OK-151) runs across Keystone Dam in northeastern Oklahoma. Its entire length is within