First of all the City of Tulsa / State of Oklahoma radio system should not be considered the “OHP” system. OHP is one of many agencies that utilize this statewide system. As I have said before any radio that is programmed to work on the City of Tulsa / State of Oklahoma system can operate anywhere there is an 800 City of Tulsa / State of Oklahoma tower. When municipal agencies are setup on the system they are programmed to operate off the tower or towers that are closest to their specific city. For example Sapulpa PD would work off the Tulsa or Bristow towers. This is also the case for specific channels on the OHP system. For example, when you are in Tulsa you will not here OHP Troop A Metro unless one of their units is affiliating in the Tulsa area. When it comes to County Agencies they are usually programmed to have their main dispatch channel work anywhere on the state system but the other channels work in their local county area. This prevents overload on other City of Tulsa / State of Oklahoma Towers that only have a few frequencies to utilize.
However, there are exceptions to this rule. For example, someone on here said they heard some TPD channels on other towers outside of the City of Tulsa. This could happen with the click of a mouse by the main City of Tulsa dispatch or DPS communications Center reprogramming a radio over the air. These dispatchers can send a message to any specific radio and tell it to talk to any tower on the system or not to talk to anything. A good example is if an officer or trooper looses his radio the dispatcher can send a message to the specific radio and place it in lost or stolen mode. This makes the radio nothing more than a pretty paperweight.
Another example that you might here Tulsa PD in OKC is if they are patched to a regional or Statewide Channel. It just depends on what is going on and who needs to communicate where. That was the whole purpose of having a statewide system. You might also here Tulsa PD dispatching Armed Robbery calls on the Tulsa County Channels in OKC because they patch all main Tulsa City and County Channels together when they dispatch those types of calls.
The moral of this story is that the City of Tulsa/State of Oklahoma system was set up to allow any agency with 800 capabilities to talk on any 800 tower anywhere in the state. While this is not the norm, it can easily be done.