Colorado Springs Fire Department is dispatched on
DTRS talkgroup 4620.
Since you say you can hear all of Teller County, I am assuming that you are in or near Teller County. A very important concept that you need to understand about large trunked radio systems like DTRS is
affiliation. The basics of it is that a site will not carry a talkgroup unless a radio that is using that talkgroup checks in with the site. This is because sites have a limited number of frequencies that they can use and they do not want to transmit something if no system radio is listening to it.
If the site that you are listening to does not cover Colorado Springs, then it is unlikely that any CSFD radio would be affiliated to that site. This concept applies throughout the entire radio system.