Oklahoma State Highway 6 - History

History

The original State Highway 6 extended from the Texas state line near Colbert to the Kansas state line north of Vinita. When the United States Numbered Highways system was established in 1926, the vast majority of the highway was overlapped by US-75 and US-73. (Later, this corridor would form the majority of U.S. Route 69 in Oklahoma). As a result, the original SH-6 designation was decommissioned soon after the U.S. highway system's establishment.

The SH-6 designation remained unused until August 21, 1954, when it was assigned to a highway beginning at US-283 east of Mangum, extending north through Granite and Retrop, and ending at US-66 in Elk City. The highway was extended west along SH-73 to its current northern terminus on January 21, 1957.

SH-6 was extended to the south on July 7, 1975, bringing it to Altus by way of a concurrency with US-283, where it joined US-62 in another concurrency, headed west. West of Altus, the route split off and headed southwest to the Texas state line. In addition to the U.S. routes, SH-6 was concurrent with SH-44 between that route's current southern terminus and Eldorado, where it ended; thereafter, SH-6 followed SH-34 to the Red River. To remove the redundant designations, both SH-34 and SH-44 were truncated to their current southern terminus on January 5, 1987.

SH-6 was realigned twice in 2004 to allow SH-6 a straighter route in situations where it was concurrent with another highway. The first such section removed a portion of the US-283 concurrency between Blair and Granite; the second realignment took place on the SH-55 concurrency north of Retrop. Both of these changes were applied to the highway on February 2, 2004. No further changes to the highway's route have taken place since then.