Okla. Stat. tit. 69 § 1698.159
State Highway 81 from the Kansas border to the Texas border shall be designated as the "Historic Chisholm Trail Bike Route". The cost associated with signage required by this section shall be provided from private sources and shall include the cost of the initial erection of signs as well as the cost of potential replacement or reconstruction of signs. Upon receiving adequate funding from private sources and after a shoulder lane has been provided, the Department of Transportation shall cause suitable permanent markers to be placed upon the highway bearing that name. Contingent upon the availability of funds, the Department shall provide a shoulder lane designated for use by bicycle traffic on the Historic Chisholm Trail Bike Route.
Okla. Stat. tit. 69, § 1698.159