I recently discovered a highway, OK 33A, that followed Denver Avenue between 2nd Street and 3rd Street in downtown Tulsa. Old US 75/OK 33 from Frisco to Denver on 2nd Street was removed and the BOK Center stands where the road used to run. US 64/OK 51 ran along 3rd and OK 33A was a link between US 64 and US 75. I wonder if it was signed as OK 33A or if it was just signed with to signs. This map is from the 1956 Tulsa County control section map published by the Oklahoma Department of Highways.
(https://live.staticflickr.com/1768/28530879327_5b966ec46f_o.png)