Yeah, I know that. WAS ASKING for help with SPECIFIC TG's for this area, NOT the broad Tucson area, thank you.
Since you used the term TGs I assume you are generally familiar with how P25 trunked systems work, so I will speak as though speaking to someone who has a baseline familiarity. (Just let me know if the below doesn't make sense to you and I am happy to explain further, but wanted to avoid talking down to you if you're pretty familiar.)
For Northwest Fire and Pima County Sheriff, you will want to monitor the Pima County Wireless Integrated Network (PCWIN) TRS. You can read more about it at
Pima County Wireless Integrated Network (PCWIN) Trunking System, Tucson, Arizona - Scanner Frequencies. I recommend you lock on to the North Simulcast site, which will allow you to hear Pima County Sheriff North channels just fine, since those TGs are always active on that Site.
North-1 covers everything west of Campbell Ave and North of the City Limits, including the Orange Grove and LaCanada area. Basically, everything on the NW side outside the City of Tucson, Oro Valley, and Marana.
Northwest Fire is dispatched by the City of Tucson, along with Tucson Fire and about a dozen other area departments, on a common radio channel plan. Take a look at Tucson Regional Fire Dispatch talkgroups on the page linked above. Everyone is dispatched on A2. Routine calls like EMS go on A3 North or A6 West, depending on the exact area. North is basically east of I-10, South of Ina Road, and north of Speedway. West covers everything West of I-10 AND everything North of Ina Road (all the way up into Catalina for Golder Ranch Fire and beyond). So ironically, a call on the south side of Oracle & Ina is on A3 North, but a call on the NORTH side of Oracle & Ina is on A6 West. Full alarm responses (like structure fires) for all departments on this system use A7, and if that's in use by another fire they get A10, and if that's in use they get A13.
So all that said - for what you've described you want to sit on PCWIN system, North Simulcast site, and Departments Tucson Regional Fire and Pima County Sheriff, with a special focus on channels PCSO North-1 and North-2, and Tucson Regional Fire channels A2, A3, A6, A7, A10 and A13.
Hope I haven't confused you too much with the detail. Let us know if you have questions, and let us know how it works!