The City of Tulsa and OHP share the same towers inside Tulsa. Tulsa PD has access to the whole system but they are set up only to simulcast on the towers located at 61st and Sheridan and downtown. The reason for this is that if Tulsa PD were to broadcast on all towers throughout the State it would overwhelm the towers with only five or six frequencies. For example, I believe that Sapulpa radios are set up to operate on the Tulsa and Bristow towers but not any others. Tulsa County can operate on their channels in the Tulsa area but can only use their main dispatch channel when in OKC or Lexington. This was all set up in the beginning to allow maximum availability by all agencies that have access to the State system.
If TPD needs to leave Tulsa for say a pursuit into OKC then they can easily be patched into a Regional or State Mutual Aid Channel and have access to the whole system. As far as who controls the system it depends where you are. In Tulsa the TPD communications center controls all agencies that use the two Tulsa towers. This includes TPD, Sand Springs, Tulsa County, Sapulpa, OHP, and all Northeastern Oklahoma Regional Mutual Aid Channels. DPS in OKC controls all other towers, the State Mutual Aid Channels and the Central Oklahoma Regional Mutual Aid Channels.
I hope this helps!!