Here's what I found and it's been submitted.
Site 001-018 Mt Royal has a control channel of 151.43 on LCN 02-0476. Its alt CC/voice channel is 161.9375 on LCN
09-2075 - never seen a system using two different idens on the same site before. Also never seen a system that uses all 16 (well I guess 14 since the first two are 800MHz and 700MHz default plans) idens either. The list on the RRDB page is pretty much up to date as far as I can tell (it's not in the same format as either the HP1 or PRO96COM delivers).
The following sites are shown as neighbors/adjacents to Mt Royal.
001-017 (Divide): CC 151.085, LCN 02-0407
001-019 (HCSO): CC 154.235, LCN 02-1037
001-020 (Antoine Butte): CC 153.980, LCN 02-0986
001-021 (see below): CC 151.295, LCN 02-0449
001-041 (Lewistown): CC 155.07, LCN 02-1204
001-043 (Judith Peak): CC 151.1525, LCN 15-0841
Some of the above CC frequencies are not in the RRDB - this submission will ask to put them in.
I believe that 16-1005 "Havre" is actually HCSO and thus should be removed as a duplicate.
"Saco",
WQDL357, in Phillips County, appears to be the best logical choice for 001-021. Between the FCC license (cross-referenced with the broadcast CC from the neighbor data on 001-018), and the documentation mentioned below, I think Saco is 001-021.
There are a whole bunch of useful and interesting maps and documents on Montana's Public Safety Services Bureau website (
mt.gov - Montana's Official State Website). I'm not going to share the direct links because they appear to be hashed somehow, but you can access them by going to this page and looking for "Statewide Maps":
mt.gov - Montana's Official State Website
"Trunked Status Map" is the most interesting, as far as I'm concerned, with "Trunked & Mobile Outbound Coverage Map" a close second. They're very informative on learning more about this system.
Last but not least, talkgroup 855 is definitely highway patrol - whichever detachment/troop/division/etc works in the area served by the Mt Royal tower. Possibly someone working Highway 2 between Shelby and Havre?