Okla. Stat. tit. 69, § 69-1705.2: Restaurants and dump stations

The Oklahoma Turnpike Authority and Transportation Commission

are hereby directed to cause a reasonable number of public restroom

facilities and dump stations for recreational motor vehicles to be

installed along both sides of the turnpikes and interstate highways

in this state which will be accessible to motorists utilizing such

turnpikes and highways at reasonable periodic intervals.