IIRR, Shreveport and Texarkana were once considered separate, but have since been one for many years.
Dallas-Fort Worth I believe has been one all the time (even though the owner of the Fort Worth NBC station (then WBAP, now KXAS) didn't care whether Dallas could see his station or not (old petty city rivalry....) till NBC threatened to pull his affiliation if he didn't put his signal on a better tower/antenna so the one signal could be seen by the whole market), as opposed to its' radio history, where for many years, Dallas and Fort Worth were considered separate.