Larimer County Fire traffic today

I'm hearing traffic on Larimer county talk group 9157. It's PFA engine 7 and command. Sounds like some trail and a rescue. I hear brush fire too. Sounds like an injured person out in no mans land.



Question: Why is there a Larimer county talk group? Couldn't you use your own channel or mutual aid?



Question number 2: What or who comes up with the talk group assignments for the DTRS? Is it just a request from the departments or what?



TIA! :D