I dug around in my files and notebooks and found a few things. I did find a document that is likely to be the same as what you are looking at. Here are my observations.
The 171.5750/164.1750 pair is the "River Net" on the Bridger-Teton NF. There is one group in the 16 group BK radio program titled "River Crew" and that net is listed there. The River Net also shows up on the BTF's first two groups, both of which are admin groups, not fire specific. However, all the listings show it on the Pow Wow repeater only. The other repeater locations make sense though, with Rosie's Ridge providing coverage for the Gros Ventre River, the Sage Mtn. repeater looks like it might cover the Grey's River and the Cottonwood Mtn. covering the Green River. Cottonwood doesn't make much sense for the Green River though as only the upper stretches of that river are on the forest where it would seem like the repeaters on Pinion Ridge and Bacon Ridge are closer. The Cottonwood repeater is located between the BTF's Wind River and Wyoming ranges in what appears to be a large area of private and BLM land, but probably provides good coverage for the lower slopes of those ranges that might be in the shadows of higher repeaters. I know of one other national forest with a dedicated "River Net" and that is the Salmon-Challis. It covers the famous "Middle Fork" run of the Salmon River and the Middle Fork Ranger District with 3 repeaters.
As a funny aside, I couldn't pronounce "Gros Ventre" when I was young and in my mind I thought it was "Gross Venture," ha, ha. It is actually pronounced "grow Vaunt." It is obviously French, just like the name "Teton." "Gros Ventre" is a much more unattractive word, that sounds kind of grand and romantic if you don't speak French, but it isn't at all. It means "big belly" in French. I'll continue to think "Grand Teton" sounds great, but "Gros Ventre" makes me think about a bunch of guys at home watching football on a big screen while drinking beer and slamming down Fritos and spicy bean dip.
Here are the repeaters for the forest:
170.5000/164.1000 North Zone Net. Appears to be used by the Clarks Fork (RD#1), Greybull (RD#2) and Wapiti (RD#4) Ranger Districts. These 3 districts are currently administered by one district ranger.
172.3250/164.8250 Clarks Fork/Washakie Net. I don't know why the forest labels it with "Clarks Fork" as it is really the south net for the Washakie (RD#3) Ranger District according to the repeater locations listed for it. If they assign nets based on location like the North Zone, this could also be labeled the South Zone Net.
172.3750/164.8750 Wind River Net. This is used by the Wind River (RD#5) Ranger District. This could also be labeled as the Central Zone Net.
168.675 R2 Tac. This is listed the same way on several Region 2 (Rocky Mountain) frequency lists. I think it is safe to say this is the R2 tac. Regions have to assign nets for a region to eliminate use of the NIFC tacs on initial attack incidents. Regions 1 (Northern ), 2 (Rocky Mountain) , 3 (Southwestern), 4 (Intermountain) and 5 (Pacific Southwest) all have regional tacs, with regions 3, 4 and 5 having at least 3 regional tacticals. Regions 8 (Southern) and 9 (Eastern) share one tactical frequency.
169.9500 simplex with a 110.9 tone is labeled "SOA SHF." This is listed in the Shoshone NF Group 13 "National Homeland Security." The addition of "SHF" could be inferred that this is not a regional SOA, but unique to the Shoshone. It can also be inferred as a regional net where the Shoshone is assigned a tone of 110.9 and that other forest have the same frequency with different tones as you mentioned. This is supported by this channel:
169.9500/165.2250 is shown "R2 SOA Repeater (Forest specific tones)." This agrees with your view of other forests using this frequency simplex or for repeaters and then having a tone assigned to each forest. . I've not seen that on other R2 forest frequency lists. I will double check my info for the region to see if I missed it.
168.7500 simplex, no tone, with the label "Shoshone TAC." It shows up more than once in the 16 group list the forest has. It looks like the people on this forest have 3 options for tacticals, the R2 tac, the R2 SOA and the Shoshone NF tac.
The group 13 I mentioned above has the VTACS as well as the VFires 21-26, the two VMeds as wekk as VLaw's 31 and 32. Those are well known.
One final observation, the "Timber" frequency shows a radio display label of "GYPO." A Google search of this in relation to logging defines the term as an independent, small scale, logger. A FCC license search for 151.9250 in Wyoming did not show anyone in logging with a license for the frequency. Somehow it would seem that independent loggers have adopted this as their frequency in the area.
Thanks for your post zerg901, I took a harder look at my Shoshone and Bridger-Teton NF's pages.