Chevron for Parker and Lonetree 100% of the time is highly likely.
DCSO on the other hand....
What you are running into is the nature of the radio system. DTRS is not a simulcast system it is a roaming system. The DCSO primary talk-group "A" will end up on multiple sites as 99% of the time everybody will be on it. Now when a tac or car to car event occurs the only towers that will have that talk-group (B, C, D etc...) are where the units on that talk-group are affiliated with. So yes you will miss some of the non-primary talk-groups if units on that talk-group are not affiliated with the tower YOU are monitoring. This is very true especially when you are dealing with a county with varying terrain.
Phil.